HEAT-HEALTH GLOSSARY

The HIGH Horizons consortium considers this glossary as a global good, a resource for those working in both climate and health research to share related terminology and advance heat-health research. HIGH Horizons invites everyone to improve the definitions or to add relevant heat-health terms in GitHub.

The glossary was developed within the context of the HIGH Horizons project and builds on existing glossaries from the Global Heat Health Information Network (GHHIN), the Intergovernmental Panel on Climate Change (IPCC) and the World Health Organization (WHO). Reference is made to all sources used. The contributions of the HIGH Horizons partners to the glossary are gratefully acknowledged.

Suggested citation:
HIGH Horizons consortium. Heat-health glossary. Zenodo; 2024. DOI10.5281/zenodo.10562027. License CC BY4.

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Acute respiratory infection (ARI): An acute respiratory tract disease that is caused by an infectious agent. Although the spectrum of symptoms of ARI may vary, the onset of symptoms is typically rapid, ranging from hours to days after infection. Symptoms include fever, cough and, often, sore throat, coryza, shortness of breath, wheezing, or difficulty in breathing. The pathogens that cause this disease include influenza virus, parainfluenza virus, rhinovirus, respiratory syncytial virus (RSV) and severe acute respiratory syndrome coronavirus (SARSCoV).
Source: World Health Organization. Infection prevention and control of epidemic-and pandemic prone acute respiratory infections in health care. WHO Guidelines. Geneva: World Health Organization; 2014. https://www.who.int/publications/i/item/infection-prevention-and-control-of-epidemic-and-pandemic-prone-acute-respiratory-infections-in-health-care.

Adaptation: The process of adjustment to actual or expected climate and its effects. In human systems, adaptation seeks to moderate or avoid harm or exploit beneficial opportunities. Types of adaptation are categorized as green/blue (urban greening), grey (early warning systems) and soft (messaging and education around cooling strategies) by the European Environment Agency.
Sources:
* IPCC. Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte V, Zhai P, Pirani A, Connors SL, Péan C, Berger S, et al. (eds.)]. Cambridge: Cambridge University Press; 2021. doi:10.1017/9781009157896.
* Boteler B, Abhold K, Tröltzsch J, Penha-Lopes G, Fonseca AL, Campos I, et al. Experiences in bottom-up adaptation approaches in Europe and elsewhere: Deliverable D4.2. 2015.

Air humidity: The concentration of water vapor present in the air is also known as ‘absolute humidity’ or ‘humidity ratio’. It can also be referred to as ‘specific’ (mass of water vapor in a unit mass of moist or dry air), as the partial water vapour pressure in Pa, or ‘relative’ (the ratio of the partial to the saturated water vapour pressure at the same temperature and absolute pressure – percent or fraction).
Source: International Organization for Standardisation. ISO 7726:1998 Ergonomics of the thermal environment – Instruments for measuring physical quantities. https://www.iso.org/standard/14562.html [Accessed 16th January 2024].

Air pollution: Degradation of air quality with negative effects on human health or the natural or built environment due to the introduction, by natural processes or human activity, into the atmosphere of substances (gases, aerosols) which have a direct (primary pollutants) or indirect (secondary pollutants) harmful effect.
Source: IPCC. Annex I: Glossary [Matthews JBR (ed.)]. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte V, Zhai P, Pörtner HO, Roberts D, Skea J, Shukla PR, et al. (eds.)]. Cambridge: Cambridge University Press; 2018. doi:10.1017/9781009157940.008.

Air quality indices: An aggregated evaluation of the pollutant load of the atmosphere across multiple constituents, generally developed to compare environmental conditions to biological outcomes with an emphasis on human health. The indices also provide a concise method of informing the general public regarding atmospheric conditions by incorporating a suite of pollutants into one single measure. The method of aggregation varies from index to index, with some emphasising the single pollutant observed at the highest/most threatening concentration, whereas others consider the effects of all pollutants simultaneously (Kyrkilis et al. 2007). In the US, the air quality index is determined by the maximum concentration of ozone, particulate pollution, carbon monoxide, sulphur dioxide, and nitrogen dioxide, where the concentration of each pollutant is normalized on a unitless 1–500 scale, where a value of 100 corresponds to the relevant national ambient air quality standard. The overall index value is set as that associated with the highest normalised score for any individual variable (Bishoi et al. 2009). A similar system based on the pollutant with the highest relative concentration is used in the UK, but values are converted to a 1–10 scale for communication to the public (Holgate 2011).
Sources:
* Global Heat Health Information Network. GHHIN glossary. https://ghhin.org/glossary/ [Accessed 16th January 2024].
* Gosling SN, Bryce EK, Dixon PG, Gabriel KM, Gosling EY, Hanes JM, et al. A glossary for biometeorology. International Journal of Biometeorology. 2014;58(2): 277–308. doi: 10.1007/s00484-013-0729-9. Epub 2014 Feb 19.

References:
* Kyrkilis G, Chaloulakou A, Kassomenos PA. Development of an aggregate air quality index for an urban Mediterranean agglomeration: relation to potential health effects. Environ Int. 2007;33: 670–676.
* Bishoi B, Prakash A, Jain VK. A comparative study of air quality index based on factor analysis and US-EPA methods for an Urban Environment. Aerosol Air Qual Res. 2009;9: 1–17.
* Holgate S. Review of the UK Air quality index. A report by the Committee on the medical effects of air pollutants. London: Health Protection Agency; 2011.

Air temperature: The temperature of the atmosphere which represents the average kinetic energy of the molecular motion in a small region and is defined in terms of a standard or calibrated thermometer in thermal equilibrium with the air.
Source: General Multilingual Environmental Thesaurus. Air temperature. https://www.eionet.europa.eu/gemet/en/concept/281 [Accessed 18th January 2024].

Ambient temperature (Ta): The average temperature of a gaseous or liquid environment (usually air or water) surrounding a body, as measured outside the thermal and hydrodynamic boundary layers that overlay the body [°C].
Synonym: temperature, dry bulb (in a gaseous environment).
Sources:
* Global Heat Health Information Network. GHHIN glossary. https://ghhin.org/glossary/ [Accessed 16th January 2024].
* International Union of Physiological Sciences (IUPS) – Thermal Commission. Glossary of terms for thermal physiology, 3rd edn. Jpn J Physiol. 2001;51: 245–280.

Anaemia: Anaemia is defined as a haemoglobin concentration below a specified cut-off point; that cut-off point depends on the age, gender, physiological status, smoking habits and altitude at which the population being assessed lives. WHO defines anaemia in children aged under 5 years and pregnant women as a haemoglobin concentration <110 g/L at sea level.
Source: World Health Organization. Haemoglobin concentrations for the diagnosis of anaemia and assessment of severity. Vitamin and Mineral Nutrition Information System. Geneva: World Health Organization; 2011. https://www.who.int/publications/i/item/WHO-NMH-NHD-MNM-11.1.

Anxiety disorders: Anxiety disorders are characterised by excessive fear and worry and related behavioural disturbances. Symptoms are severe enough to result in significant distress or significant impairment in functioning.
Source: World Health Organization. Mental Health Disorders. https://www.who.int/news-room/fact-sheets/detail/mental-disorders [Accessed 18th January 2024].

Apparent temperature: A generic term used to cover a range of biometeorological indices that estimate an individual’s perceived temperature, based upon the air temperature and humidity and/or wind speed. It represents how the climate “feels” to the human body (Robinson 2001). The term was put forwards by Steadman (1979a, b). Examples of apparent temperature indices include: the Heat Index (HI), the Heat Stress Index (HSI), Humidex, Wet Bulb Globe Temperature (WBGT), Universal Thermal Climate Index (UTCI), the Steadman Apparent Temperature Index and the new Wind Chill Equivalent Temperature (WCET) index. While the term “apparent temperature” is generic, it should be noted that some studies refer to the Steadman Apparent Temperature Index and the HI as the “apparent temperature”.
Sources:
* Global Heat Health Information Network. GHHIN glossary. https://ghhin.org/glossary/ [Accessed 16th January 2024].
* Gosling SN, Bryce EK, Dixon PG, Gabriel KM, Gosling EY, Hanes JM, et al. A glossary for biometeorology. International Journal of Biometeorology. 2014;58(2): 277–308. doi: 10.1007/s00484-013-0729-9. Epub 2014 Feb 19.

References:
* Robinson PJ. On the definition of a heat wave. J Appl Meteorol. 2001;40: 762–775.
* Steadman R. The assessment of sultriness. Part I: a temperature-humidity index based on human physiology and clothing science. J Appl Meteorol. 1979;18: 861–873.
* Steadman R. The assessment of sultriness. Part II: effects of wind, extra radiation and barometric pressure on apparent temperature. J Appl Meteorol. 1979;18: 878–885.

Asymptomatic bacteriuria (ASB): Defined as true bacteriuria in the absence of specific symptoms of acute urinary tract infection, ASB is common in pregnancy, with rates as high as 74% . Escherichia coli is associated with up to 80% of isolates. Other pathogens include Klebsiella species, Proteus mirabilis and group B streptococcus (GBS). While ASB in nonpregnant women is generally benign, in pregnant women obstruction to the flow of urine by the growing foetus and womb leads to stasis in the urinary tract and increases the likelihood of acute pyelonephritis. If untreated, up to 45% of pregnant women with ASB may develop this complication, which is associated with an increased risk of preterm birth.
Source: World Health Organization. WHO recommendations on antenatal care for a positive pregnancy experience. Geneva: World Health Organization; 2016. https://www.who.int/publications/i/item/9789241549912.

Blood glucose levels (maternal): Hyperglycaemia first detected at any time during pregnancy should be classified as either gestational diabetes mellitus (GDM) or diabetes mellitus in pregnancy, according to WHO criteria.
This is not a recommendation on routine screening for hyperglycaemia in pregnancy. It has been adapted and integrated from the WHO publication ‘Diagnostic criteria and classification of hyperglycaemia first detected in pregnancy’ (2013), which states that GDM should be diagnosed at any time in pregnancy if one or more of the following criteria are met:
* fasting plasma glucose 5.1–6.9 mmol/L (92–125 mg/dL)
* 1-hour plasma glucose > 10.0 mmol/L (180 mg/dL) following a 75 g oral glucose load
* 2-hour plasma glucose 8.5–11.0 mmol/L (153–199 mg/dL) following a 75 g oral glucose load.
Diabetes mellitus in pregnancy should be diagnosed if one or more of the following criteria are met:
* fasting plasma glucose > 7.0 mmol/L (126 mg/dL)
* 2-hour plasma glucose > 11.1 mmol/L (200 mg/dL) following a 75 g oral glucose load
* random plasma glucose > 11.1 mmol/L (200 mg/dL) in the presence of diabetes symptoms.
Source: World Health Organization. WHO recommendations on antenatal care for a positive pregnancy experience. Geneva: World Health Organization; 2016. https://www.who.int/publications/i/item/9789241549912.

Reference:
World Health Organization. Diagnostic criteria and classification of hyperglycaemia first detected in pregnancy. Geneva: World Health Organization; 2013. https://www.who.int/publications/i/item/WHO-NMH-MND-13.2.

Body core temperature: Body core temperature is a useful heat stress metric. Conventional measurement of body temperature usually involves ingestion of an electronic pill or use of a rectal thermometer, which will not be feasible in this field study. Instead, body temperature of the health care workers involved in the HIGH Horizons time-motion study will be estimated with a non-invasive sensor attached to torso with a strap or a medical patch such as the following CORE Body Temperature Sensor at corebodytemp.com.
Sources:
* HIGH Horizons. Healthcare worker study. Deliverable D2.10. Forthcoming. https://www.high-horizons.eu/.
* CORE. Core body temperature. https://corebodytemp.com/ [Accessed 16th January 2024].

CO2-equivalent: The amount of carbon dioxide (CO₂) emission that would cause the same integrated radiative forcing or temperature change, over a given time horizon, as an emitted amount of a greenhouse gas (GHG) or a mixture of GHGs. There are a number of ways to compute such equivalent emissions and choose appropriate time horizons. Most typically, the CO₂-equivalent emission is obtained by multiplying the emission of a GHG by its global warming potential (GWP) for a 100-year time horizon. For a mix of GHGs it is obtained by summing the CO₂-equivalent emissions of each gas. CO₂-equivalent emission is a common scale for comparing emissions of different GHGs but does not imply equivalence of the corresponding climate change responses. There is generally no connection between CO₂-equivalent emissions and resulting CO₂-equivalent concentrations.
Source: IPCC. Annex I: Glossary [Matthews JBR (ed.)]. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte V, Zhai P, Pörtner HO, Roberts D, Skea J, Shukla PR, et al. (eds.)]. Cambridge: Cambridge University Press; 2018. doi:10.1017/9781009157940.008.

Capacity building: In health promotion, capacity building is the development of knowledge, skills, commitment, partnerships, structures, systems and leadership to enable effective health promotion actions.
Source: World Health Organization. Health promotion glossary of terms 2021. Geneva: World Health Organization; 2021. https://www.who.int/publications/i/item/9789240038349.

Carbon footprint: The total amount of greenhouse gases that are emitted into the atmosphere each year by a person, family, building, organization, or company. A persons carbon footprint includes greenhouse gas emissions from fuel that an individual burns directly, such as by heating a home or riding in a car. It also includes greenhouse gases that come from producing the goods or services that the individual uses, including emissions from power plants that make electricity, factories that make products, and landfills where trash gets sent.
Source: United States Environmental Protection Agency. Glossary of Climate Change Terms. https://19january2017snapshot.epa.gov/climatechange/glossary-climate-change-terms_.html#C [Accessed 18th January 2024].

Caregiver: A caregiver is a person very closely attached to the child and responsible for the child’s care and support. Primary caregivers include parents, families and other people who are directly responsible for the child at home. They also include carers outside the home, such as those working in organized childcare.
Source: World Health Organization and the United Nations Children’s Fund. Investing in our future: a comprehensive agenda for the health and well-being of children and adolescents. Geneva: World Health Organization and the United Nations Children’s Fund; 2021. https://iris.who.int/handle/10665/350239.

Child health: Child health is a state of physical, mental, intellectual, social and emotional well-being and not merely the absence of disease or infirmity. Healthy children live in families, environments, and communities that provide them with the opportunity to reach their fullest developmental potential.
Source: World Health Organization and the United Nations Children’s Fund. Investing in our future: a comprehensive agenda for the health and well-being of children and adolescents. Geneva: World Health Organization and the United Nations Children’s Fund; 2021. https://iris.who.int/handle/10665/350239.

Child maltreatment: The abuse and neglect of children under 18 years of age. It includes all types of physical and/or emotional ill-treatment, sexual abuse, neglect, negligence and commercial or other exploitation, which results in actual or potential harm to the child’s health, survival, development or dignity in the context of a relationship of responsibility, trust or power.
Source: World Health Organization. Improving early childhood development: WHO guideline. Geneva: World Health Organization; 2020. https://www.who.int/publications/i/item/97892400020986.

Climate: Climate in a narrow sense is usually defined as the average weather, or more rigorously, as the statistical description in terms of the mean and variability of relevant quantities over a period of time ranging from months to thousands or millions of years. The classical period for averaging these variables is 30 years, as defined by the World Meteorological Organization. The relevant quantities are most often surface variables such as temperature, precipitation and wind.
Climate in a wider sense is the state, including a statistical description, of the climate system.
Source: United States Environmental Protection Agency. Glossary of Climate Change Terms. https://19january2017snapshot.epa.gov/climatechange/glossary-climate-change-terms_.html#C [Accessed 18th January 2024].

Climate change: Climate change refers to a change in the state of the climate that can be identified (e.g., by using statistical tests) by changes in the mean and/or the variability of its properties and that persists for an extended period, typically decades or longer. Climate change may be due to natural internal processes or external forcings such as modulations of the solar cycles, volcanic eruptions and persistent anthropogenic changes in the composition of the atmosphere or in land use. Note that the Framework Convention on Climate Change (UNFCCC), in its Article 1, defines climate change as: ‘a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods.’ The UNFCCC thus makes a distinction between climate change attributable to human activities altering the atmospheric composition and climate variability attributable to natural causes.
Source: IPCC. Annex I: Glossary [Matthews JBR (ed.)]. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte V, Zhai P, Pörtner HO, Roberts D, Skea J, Shukla PR, et al. (eds.)]. Cambridge: Cambridge University Press; 2018. doi:10.1017/9781009157940.008.

Climate tipping point: A level of change in system properties beyond which a system reorganizes, often abruptly, and does not return to the initial state even if the drivers of the change are abated. For the climate system, it refers to a critical threshold when global or regional climate changes from one stable state to another stable state.
Source: IPCC. Annex I: Glossary [Matthews JBR (ed.)]. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte V, Zhai P, Pörtner HO, Roberts D, Skea J, Shukla PR, et al. (eds.)]. Cambridge: Cambridge University Press; 2018. doi:10.1017/9781009157940.008.

Climate-resilient health systems: Climate-resilient health systems are defined as those with the ability to anticipate, respond to, cope with, recover from and adapt to climate-related shocks and stresses, so as to bring sustained improvements in population health, despite an unstable climate.
Source: World Health Organization. Operational framework for building climate resilient health systems. Geneva: World Health Organization; 2015. https://www.who.int/publications-detail-redirect/9789241565073.

Co-benefits: Co-benefits are mutually positive outcomes for health and other sectors within governments, organizations and communities. Co-benefits across sectors and society at large can be achieved when health considerations are transparently taken into account in policy-making, resource allocation and service delivery.
Governments have a range of priorities in which health and equity do not automatically gain precedence over other policy objectives. The policy levers for action on the determinants of health often sit outside the remit of the health sector. Co-benefits emerge when health considerations are transparently taken into account in policy-making, for example, as a result of health impact assessment. Achieving co-benefits is important to ‘Health in all policies’ providing a framework for regulation and practical tools that combine health, social and equity goals with economic development.
Sources:
* World Health Organization. The Helsinki statement: Framework for action. Geneva: World Health Organization; 2014. https://www.who.int/publications/i/item/9789241506908.
* World Health Organization. Health in all policies: training manual. Geneva: World Health Organization; 2015. https://www.who.int/publications/i/item/9789241507981.

Complementary feeding: Around the age of 6 months, an infant’s need for energy and nutrients starts to exceed what is provided by breast milk, and complementary foods are necessary to meet those needs. An infant of this age is also developmentally ready for other foods. This transition is referred to as complementary feeding. WHO and UNICEF recommend introduction of nutritionally-adequate and safe complementary (solid) foods at 6 months together with continued breastfeeding up to 2 years of age or beyond.
Source: World Health Organization. Infant and young child feeding. https://www.who.int/news-room/fact-sheets/detail/infant-and-young-child-feeding [Accessed 18th January 2024].

Congenital disorders: Congenital disorders can be defined as structural or functional anomalies (for example, metabolic disorders) that occur during intrauterine life and can be identified prenatally, at birth, or sometimes may only be detected later in infancy, such as hearing defects. Broadly, congenital refers to the existence at or before birth. They are also known as congenital abnormalities, congenital malformations or birth defects.
Source: World Health Organization. Congenital disorders. https://www.who.int/news-room/fact-sheets/detail/birth-defects [Accessed 18th January 2024].

Continued breastfeeding: Breastfeeding up to 2 years or beyond.
Source: World Health Organization. Infant and young child feeding. https://www.who.int/news-room/fact-sheets/detail/infant-and-young-child-feeding [Accessed 18th January 2024].

Deadly days: Daily maximum wet-bulb temperature over 24°C; Unit: Number of days.
Source: Lee J, Mast JC, Dessler AE. The effect of forced change and unforced variability in heat waves, temperature extremes, and associated population risk in a CO2-warmed world. Atmospheric Chemistry and Physics. 2021;21(15): 11889–11904. doi:10.5194/ACP-21-11889-2021.

Decarbonisation: The process by which countries, individuals or other entities aim to achieve zero fossil carbon existence. Typically refers to a reduction of the carbon emissions associated with electricity, industry and transport.
Source: IPCC. Annex I: Glossary [Matthews JBR (ed.)]. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte V, Zhai P, Pörtner HO, Roberts D, Skea J, Shukla PR, et al. (eds.)]. Cambridge: Cambridge University Press; 2018. doi:10.1017/9781009157940.008.

Dehydration: Dehydration can be defined broadly as the process of losing body water which leads eventually to hypohydration.
Source: EFSA Panel on Dietetic Products, Nutrition, and Allergies (NDA). Scientific Opinion on Dietary reference values for water. EFSA Journal. 2010; 8(3): 1459. doi:10.2903/j.efsa.2010.1459.

Determinants of health: Determinants of health are the range of personal, social, economic and environmental factors that determine healthy life expectancy of individuals and populations.
Source: World Health Organization. Health promotion glossary of terms 2021. Geneva: World Health Organization; 2021. https://www.who.int/publications/i/item/9789240038349.

Early childhood development: A period of rapid, critical development of a child’s cognitive, physical, language, motor, social and emotional development between conception and 8 years of age.
Source: World Health Organization and the United Nations Children’s Fund. Investing in our future: a comprehensive agenda for the health and well-being of children and adolescents. Geneva: World Health Organization and the United Nations Children’s Fund; 2021. https://iris.who.int/handle/10665/350239.

Early initiation of breastfeeding: Early initiation of breastfeeding, within one hour of birth.
Source: World Health Organization. WHO recommendations on maternal and newborn care for a positive postnatal experience. Geneva: World Health Organization; 2022. https://www.who.int/publications/i/item/9789240045989.

Early warning system (EWS): An adaptive measure for climate change, using integrated communication systems to help communities prepare for hazardous climate-related events. A successful EWS saves lives and jobs, land and infrastructures and supports long-term sustainability.
Source: United Nations. Early Warning Systems. https://www.un.org/en/climatechange/climate-solutions/early-warning-systems# [Accessed 18th January 2024].

Eclampsia: Eclampsia is a condition characterized by the occurrence of generalized seizures in women with pre-eclampsia, provided that the tonic–clonic seizures are not attributable to other causes (e.g. epilepsy).
Source: World Health Organization. WHO recommendations for prevention and treatment of pre-eclampsia and eclampsia. Geneva: World Health Organization; 2011. https://www.who.int/publications/i/item/9789241548335.

Embodied carbon: Embodied carbon emissions of goods, also known as embedded carbon emissions, refer to the greenhouse gas emissions generated during the production and transportation of goods, from the extraction of raw materials to the manufacturing process and final delivery to the consumer.
Source: Third Generation Environmentalism Ltd (E3G). Embodied carbon emissions: meaning and measurements. https://www.e3g.org/news/embodied-carbon-emissions-meaning-and-measurements/ [Accessed 18th January 2024].

Emission hotspot: Area or process within an organization that produce a disproportionately high amount of greenhouse gas emissions.
Source: Wiebe KS. Identifying emission hotspots for low carbon technology transfers. Journal of Cleaner Production. 2018;194: 243-252. doi:10.1016/j.jclepro.2018.05.003.

Emission scopes: The different categories of emissions that are accounted for in a carbon footprint assessment.
Source: Carbon Trust. What are Scope 3 emissions and why do they matter? https://www.carbontrust.com/our-work-and-impact/guides-reports-and-tools/what-are-scope-3-emissions-and-why-do-they-matter [Accessed 18th January 2024].

Emissions: The release of greenhouse gases into the atmosphere. Emissions can be direct, such as from burning fossil fuels, or indirect, such as from the production of electricity used to power a building or process. Emissions are typically measured in tonnes of CO₂ equivalent (tCO₂e).
Source: United Nations Framework Convention on Climate Change. Glossary. https://unfccc.int/resource/cd_roms/na1/ghg_inventories/english/8_glossary/Glossary.htm [Accessed 17th January 2024].

Excess Heat Factor (EHF): Significant Excess Heat Factor (EHF) is where the daily mean temperature is higher than the 95th climatology percentile for 3 days or more; Whereas Acclimatized Excess Heat Factor is where the difference between a 3 day average and a 30 day average is positive; Unit: Dimensionless (Normalized Factor).
Sources:
* Nairn J, Ostendorf B, Bi P. Performance of Excess Heat Factor Severity as a Global Heatwave Health Impact Index. International Journal of Environmental Research and Public Health. 2018; 15(11): 2494. doi:10.3390/ijerph15112494.
* Varghese BM, Barnett AG, Hansen AL, Bi P, Nairn J, Rowett S, et al. Characterising the impact of heatwaves on work-related injuries and illnesses in three Australian cities using a standard heatwave definition – Excess Heat Factor (EHF). Journal of Exposure Science & Environmental Epidemiology. 2019;29(6): 821–830. doi:10.1038/s41370-019-0138-2.

Exclusive breastfeeding: Breastfeeding initiated within the first hour of birth and carried out exclusively for the first 6 months of life – meaning no other foods or liquids are provided, including water.
Source: World Health Organization. Infant and young child feeding. https://www.who.int/news-room/fact-sheets/detail/infant-and-young-child-feeding [Accessed 18th January 2024].

Exposure: A realized contact between a person and an indoor or outdoor environment that poses a risk of increases in body core temperature and/or perceived discomfort.
Source: Kuras ER, Richardson MB, Calkins MM, Ebi KL, Hess JJ, Kintziger KW, et al. Opportunities and Challenges for Personal Heat Exposure Research. Environ Health Perspect. 2017;125(8): 085001. doi:10.1289/EHP556. PMID: 28796630; PMCID: PMC5783663.

Extreme temperature range (ETR): Difference between the highest temperature and lowest temperature in a year; Unit: °C.
Source: Perkins SE. A review on the scientific understanding of heatwaves—Their measurement, driving mechanisms, and changes at the global scale. Atmospheric Research. 2015;164-165: 242–267. doi:10.1016/j.atmosres.2015.05.014.

Foetal death: Foetal death is death of a foetus prior to the complete expulsion or extraction from a woman. It may be diagnosed in utero by the absence of foetal heart sounds, confirmed by imaging techniques where available, or at delivery by absence of signs of life at birth or after attempted resuscitation.
Source: World Health Organization. European Health Information Gateway. https://gateway.euro.who.int/en/indicators/hfa_82-1160-fetal-deaths-per-1000-births/ [Accessed 18th January 2024).

Foetal growth restriction: Foetal growth restriction is defined as the failure of the foetus to meet its growth potential due to a pathological factor, most commonly placental dysfunction.
Source: Melamed N, Baschat A, Yinon Y, Athanasiadis A, Mecacci F, Figueras F, et al. FIGO (International Federation of Gynaecology and Obstetrics) initiative on foetal growth: best practice advice for screening, diagnosis, and management of foetal growth restriction. Int J Gynaecol Obstet. 2021;152(Suppl 1): 3–57. doi: 10.1002/ijgo.13522. PMID: 33740264; PMCID: PMC8252743.

Gender responsive: A policy or programme that considers gender norms, roles and inequality and has measures to actively reduce their harmful effects.
Source: World Health Organization. WHO guideline on self-care interventions for health and well-being, 2022 revision. Geneva: World Health Organization; 2022. https://www.who.int/publications/i/item/9789240052192.

Gestational age: The duration of gestation is measured from the first day of the last normal menstrual period. Gestational age is expressed in completed days or completed weeks (e.g. events occurring 280 to 286 completed days after the onset of the last normal menstrual period are considered to have occurred at 40 weeks of gestation).
Source: World Health Organization. Definitions and indicators in Family Planning Maternal & Child Health and Reproductive Health used in the WHO Regional Office for Europe. Copenhagen : WHO Regional Office for Europe; 2000. https://iris.who.int/handle/10665/108284.

Gestational diabetes: Hyperglycaemia first detected at any time during pregnancy is defined as gestational diabetes mellitus (GDM) if one or more of the following criteria are met:
* fasting plasma glucose 5.1–6.9 mmol/L (92–125 mg/dL)
* 1-hour plasma glucose > 10.0 mmol/L (180 mg/dL) following a 75 g oral glucose load
* 2-hour plasma glucose 8.5–11.0 mmol/L (153–199 mg/dL) following a 75 g oral glucose load
Source: World Health Organization. Diagnostic criteria and classification of hyperglycaemia first detected in pregnancy. Geneva: World Health Organization; 2013. https://www.who.int/publications/i/item/WHO-NMH-MND-13.2.

Gestational hypertension: New hypertension presenting after 20 weeks of pregnancy without significant proteinuria. Hypertension is defined as blood pressure of 140 mmHg systolic or higher, or 90 mmHg diastolic or higher. Severe hypertension is defined as blood pressure over 160 mmHg systolic or over 110 mmHg diastolic.
Source: National Institute for Health and Care Excellence (NICE), Hypertension in pregnancy: diagnosis and management: NICE guideline [NG133]. 2023. https://www.nice.org.uk/guidance/NG133 [Accessed 18th January 2024].

Globe temperature: With a known air temperature (and air speed), the globe temperature can estimate the mean radiant temperature.
A simplified globe thermometer consists of a globe (ping-pong ball) in the centre of which is placed a temperature sensor. The temperature measured by the sensor element is an integrated measure of the radiant and air temperatures and it depends on the energy balance between the convective and radiant heat exchanges of the globe. The mean radiant temperature, and consequently the operative temperature, is not uniform in the room, but vary according to the location.
Source: Bedford T, Warner CG. The Globe Thermometer in Studies of Heating and Ventilation. Epidemiology and Infection. 1934;34(4): 458–473. doi:10.1017/S0022172400043242.

Greenhouse gas: Any gas that absorbs infrared radiation in the atmosphere. Greenhouse gases include, but are not limited to, water vapor, carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), hydrochlorofluorocarbons (HCFCs), ozone (O₃), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulphur hexafluoride (SF₆).
Source: United Nations Framework Convention on Climate Change. Glossary. https://unfccc.int/resource/cd_roms/na1/ghg_inventories/english/8_glossary/Glossary.htm [Accessed 17th January 2024].

Greenhouse gas emissions: Releases of greenhouse gases to the atmosphere (e.g., the release of carbon dioxide during fuel combustion).
Source: United Nations Framework Convention on Climate Change. Glossary. https://unfccc.int/resource/cd_roms/na1/ghg_inventories/english/8_glossary/Glossary.htm [Accessed 17th January 2024].

Haemolysis, Elevated Liver enzymes and Low Platelets (HELLP) syndrome: HELLP syndrome is a condition defined by presence of haemolysis, elevated liver enzymes and low platelet count.
Source: National Institute for Health and Care Excellence (NICE), Hypertension in pregnancy: diagnosis and management: NICE guideline [NG133]. 2023. https://www.nice.org.uk/guidance/NG133 [Accessed 18th January 2024].

Hazard: The potential occurrence of a natural or human-induced physical event or trend that may cause loss of life, injury, or other health impacts, as well as damage and loss to property, infrastructure, livelihoods, service provision, ecosystems and environmental resources.
Source: IPCC. Annex I: Glossary [Matthews JBR (ed.)]. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte V, Zhai P, Pörtner HO, Roberts D, Skea J, Shukla PR, et al. (eds.)]. Cambridge: Cambridge University Press; 2018. doi:10.1017/9781009157940.008.

Health equity: Health equity is the absence of unfair, avoidable or remediable differences in health status among population groups defined socially, economically, demographically or geographically.
Source: World Health Organization. Health promotion glossary of terms 2021. Geneva: World Health Organization; 2021. https://www.who.int/publications/i/item/9789240038349.

Health intervention: A health intervention is an act performed for, with or on behalf of a person or population to assess, improve, maintain, promote or modify health, functioning or health conditions. Health interventions can be carried out by a broad range of health workers, including laypeople,across the full scope of health systems, and includes diagnosis, medical, surgical, mental health, primary care, allied health, functioning support, rehabilitation, traditional medicine and public health.
Source: World Health Organization. WHO guideline on self-care interventions for health and well-being, 2022 revision. Geneva: World Health Organization; 2022. https://www.who.int/publications/i/item/9789240052192.

Health worker: Health workers are defined as all people engaged in actions whose primary intent is to enhance health. While, strictly speaking, this includes unpaid carers (e.g. parents caring for sick children, and self-carers), the data available on health worker numbers are generally limited to people engaged in paid activities.
Source: World Health Organization. Abortion care guideline. Geneva: World Health Organization; 2022. https://www.who.int/publications/i/item/9789240039483.

Heat: Form of kinetic energy that flows from one body to another when there is a temperature difference between the two bodies. Heat always flows spontaneously from a hot sample of matter to a colder sample of matter. This is one way to state the second law of thermodynamics.
Source: United Nations Framework Convention on Climate Change. Glossary. https://unfccc.int/resource/cd_roms/na1/ghg_inventories/english/8_glossary/Glossary.htm [Accessed 17th January 2024].

Heat health action plan (HHAP): A heat health action plan (HHAP) provides the coordination and operating framework for planning and implementing Heat Health Warning Systems. HHAPs often specify mechanisms for interagency coordination with
defined roles and responsibilities for extreme heat responses, preparedness strategies targeting public awareness and community outreach, capacity building among health care professionals, and a range of individual actions designed to reduce health risks from extreme heat, particularly for vulnerable populations.
Source: G7 Germany. From the G7 Health Communiqué to Action: Health and Climate – Heat Preparedness through Early Warning Systems. Virtual meeting – 29 November 2022. https://ghhin.org/wp-content/uploads/G7-report-heat-EWS.pdf.

Heat health warning system: A heat health warning system (HHWS) uses climate and weather forecasts and predetermined trigger levels of heat stress to provide public advisory and initiate public health interventions designed to reduce health risks before, during, and after periods of extreme heat. HHWS are critical decision-tools commonly developed and managed jointly by designated public health professionals and meteorologists. HHWS represent a key component of wider HHAP guiding health and social service decision making and protocols for appropriate preparedness, prevention, and response action to extreme heat.
Source: G7 Germany. From the G7 Health Communiqué to Action: Health and Climate – Heat Preparedness through Early Warning Systems. Virtual meeting – 29 November 2022. https://ghhin.org/wp-content/uploads/G7-report-heat-EWS.pdf

Heat index: An apparent temperature calculation designed to determine the temperature that the human body “feels” when its evaporative cooling mechanism (perspiration) is limited due to increased relative humidity. The variables required to calculate the heat index (HI) were established originally by Steadman (1979b), but the current operational equation was created through multiple regression statistical analyses by Rothfusz (1990): EQUATION where: Ta is air temperature (°C), R is the relative humidity (%). In the United States, the National Weather Service uses the HI primarily to determine when to issue heat alerts.
Sources:
* Global Heat Health Information Network. GHHIN glossary. https://ghhin.org/glossary/ [Accessed 16th January 2024].
* Gosling SN, Bryce EK, Dixon PG, Gabriel KM, Gosling EY, Hanes JM, et al. A glossary for biometeorology. International Journal of Biometeorology. 2014;58(2): 277–308. doi: 10.1007/s00484-013-0729-9. Epub 2014 Feb 19.

References:
* Steadman RG. The assessment of sultriness. Part I: a temperature-humidity index based on human physiology and clothing science. J Appl Meteorol. 1979;18: 861–873.
* Rothfusz LP. The Heat Index “Equation” (or, More Than You Ever Wanted to Know About Heat Index). SR 90–23. Fort Worth, TX:National Oceanic and Atmospheric Administration, National Weather Service, Office of Meteorology; 1990.

Heat stress: The net heat load to which a worker is exposed from the combined contributions of metabolic heat, environmental factors, and clothing worn which results in an increase in heat storage in the body.
Source: Jacklitsch B, Williams WJ, Musolin K, Coca A, Kim J-H, Turner N. NIOSH criteria for a recommended standard: occupational exposure to heat and hot environments. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH); 2016. Publication 2016-106.

Heat stress index (HSI): A summer apparent temperature index (May–September) that computes relative heat stress comparisons of locations throughout the US, based on 30-year datasets and deviations from normal (Watts and Kalkstein 2004). It is different from the Index of Heat Stress. The heat stress index (HSI) uses the “shaded” Steadman Apparent Temperature index (Steadman 1984), cloud cover, cooling degree-days, and consecutive days of extreme heat to calculate a relative heat stress for individual locations at specific times of the warm season (Souch and Grimmond 2004). This is completed by evaluating the frequency distributions for 10-day intervals derived from the meteorological variables, with percentile values determined for each parameter. The final daily HSI (%) is based on the location of the daily summed value under the distribution curve (Watts and Kalkstein 2004). For example, a HSI of 97 % conveys that on the current date, only 3 % of days are likely to experience more stressful conditions than the day being reviewed.
Sources:
* Global Heat Health Information Network. GHHIN glossary. https://ghhin.org/glossary/ [Accessed 16th January 2024].
* Gosling SN, Bryce EK, Dixon PG, Gabriel KM, Gosling EY, Hanes JM, et al. A glossary for biometeorology. International Journal of Biometeorology. 2014;58(2): 277–308. doi: 10.1007/s00484-013-0729-9. Epub 2014 Feb 19.

References:
* Watts JD, Kalkstein LS. The development of a warm-weather relative stress index for environmental applications. J Appl Meteorol. 2004;43: 503–513.
* Steadman RG. A universal scale of apparent temperature. J Clim Appl Meteorol. 1984;23: 1674–1687.
* Souch C, Grimmond CSB. Applied climatology: heat waves. Prog Phys Geogr. 2004;28: 599–606.

Heat-related mortality: Heat-related mortality is conflating deaths occurring during the warm season and deaths attributed to heat. The latest ICD-10 codes (WHO 2016) that consider heat-related causes of death are included in T67 (effects of heat and light), which incorporates T67.0 (heatstroke and sunstroke), T67.1 (heat syncope), T67.2 (heat cramp), T67.3 (heat exhaustion, anhydrotic), T67.4 (heat exhaustion due to salt depletion), T67.5 (heat exhaustion, unspecified), T67.6 (heat fatigue, transient), T67.7 (heat oedema), T67.8 (other effects of heat and light) and T67.9 (effect of heat and light, unspecified). These have been used in recent studies; e.g. Beggs and Vaneckova (2008) but the majority of studies tend to calculate “excess mortality” (Gosling et al. 2009) from time series of all-cause mortality, or from other causes (e.g. ischemic heart disease).
Sources:
* Global Heat Health Information Network. GHHIN glossary. https://ghhin.org/glossary/ [Accessed 16th January 2024].
* Gosling SN, Bryce EK, Dixon PG, Gabriel KM, Gosling EY, Hanes JM, et al. A glossary for biometeorology. International Journal of Biometeorology. 2014;58(2): 277–308. doi: 10.1007/s00484-013-0729-9. Epub 2014 Feb 19.

References:
* World Health Organization. International Statistical Classification of Diseases and Related Health Problems. 10th Revision. Geneva: World Health Organization; 2016. https://iris.who.int/handle/10665/246208.
* Beggs PJ, Vaneckova P. Admission to hospital for effects of heat and light: NSW, 1993–94 to 2003–04. NSW Public Health Bull. 2008;19: 132–137.
* Gosling SN, Lowe JA, McGregor GR, Pelling M, Malamud B. Associations between elevated atmospheric temperature and human mortality: a critical review of the literature. Clim Chang. 2009;92: 299–341.

Heating, ventilation and air conditioning (HVAC): Heating, ventilation and air conditioning technology is used to control temperature and humidity in an indoor environment, be it in buildings or in vehicles, providing thermal comfort and healthy air quality to the occupants. HVAC systems can be designed for an isolated space, an individual building or a distributed heating and cooling network within a building structure or a district heating system. The latter provides economies of scale and also scope for integration with solar heat, natural seasonal cooling/heating etc.
Source: IPCC. Annex I: Glossary [Matthews JBR (ed.)]. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte V, Zhai P, Pörtner HO, Roberts D, Skea J, Shukla PR, et al. (eds.)]. Cambridge: Cambridge University Press; 2018. doi:10.1017/9781009157940.008.

Heatwave: A heatwave is a period of extreme high temperature that lasts several days. Heat waves can be responsible for large numbers of weather-related deaths and diseases (Kovats and Ebi 2006). No globally accepted definition of a heat wave exists (Koppe et al. 2004; Robinson 2001). Three different approaches are usually applied to determine whether a period is defined as a “heat wave” (Gosling et al. 2009; Robinson 2001). Methods for identifying heat wave days include selecting the 95th percentile of daily temperature (Beniston 2004; Gosling et al. 2007; Hajat et al. 2002), selecting absolute temperatures (Koppe and Jendritzky 2005; Matzarakis et al. 2010) [this approach is mostly used with human biometeorological indices such as the Physiological Equivalent Temperature (PET) or the Universal Thermal Climate Index(UTCI), for which levels of thermal stress are defined (e.g. Matzarakis et al. (2010; 2009) for PET)], or approaches that identify a specific synoptic classification/air mass (Hondula et al. 2013).
Sources:
* Global Heat Health Information Network. GHHIN glossary. https://ghhin.org/glossary/ [Accessed 16th January 2024].
* Gosling SN, Bryce EK, Dixon PG, Gabriel KM, Gosling EY, Hanes JM, et al. A glossary for biometeorology. International Journal of Biometeorology. 2014;58(2): 277–308. doi: 10.1007/s00484-013-0729-9. Epub 2014 Feb 19.

Heatwave amplitude: Maximum 2 meter air temperature reached in a single heatwave; Unit: °C
Source: Perkins SE, Alexander LV. On the Measurement of Heat Waves. Journal of Climate. 2013;26(13): 4500–4517. doi:10.1175/JCLI-D-12-00383.1.

Heatwave duration: Length of longest period of consecutive heatwave days in a year; Unit: No. Days.
Source: Hulley GC, Dousset B, Kahn BH. Rising Trends in Heatwave Metrics Across Southern California. Earth’s Future. 2020;8(7). doi:10.1029/2020EF001480.

Heatwave duration index (HWDI): Maximum period of at least five consecutive days where daily maximum temperature is above the 1961-1990 mean +5°C; Unit: No. Days.
Source: Perkins SE. A review on the scientific understanding of heatwaves—Their measurement, driving mechanisms, and changes at the global scale. Atmospheric Research. 2015;164-165: 242–267. doi:10.1016/j.atmosres.2015.05.014.

Heatwave frequency: Total number of heatwaves in a year; Unit: No. Days.
Source: Perkins-Kirkpatrick SE, Lewis SC. Increasing trends in regional heatwaves. Nature Communications. 2020; 11(1): 1–8. doi:10.1038/s41467-020-16970-7.

Heatwave magnitude index (HWMId): The maximum magnitude of the heat waves in a year; Unit: No. Days.
Sources:
* Ceccherini G, Russo S, Ameztoy I, Francesco Marchese A, Carmona-Moreno C. Heat waves in Africa 1981-2015, observations and reanalysis. Natural Hazards and Earth System Sciences. 2017;17(1): 115–125. doi:10.5194/nhess-17-115-2017.
* Russo S, Dosio A, Graversen RG, Sillmann J, Carrao H, Dunbar MB, et al. Magnitude of extreme heat waves in present climate and their projection in a warming world. Journal of Geophysical Research: Atmospheres. 2014;119(22): 12,500–12,512. doi:10.1002/2014JD022099.

Heatwave mean: Average 2 meter air temperature for all heatwaves in a year; Unit: °C.
Source: Perkins SE, Alexander LV. On the Measurement of Heat Waves. Journal of Climate. 2013;26(13): 4500–4517. doi:10.1175/JCLI-D-12-00383.1.

Hot days: Daily maximum 2 meter air temperature over 35°C; Unit: No. Days.
Source: Fontaine B, Janicot S, Monerie PA. Recent changes in air temperature, heat waves occurrences and atmospheric circulation in Northern Africa. J. Geophys. Res. Atmos. 2013;118: 8536–8552. doi:10.1002/jgrd.50667.

Human rights: Human rights are legal guarantees that are equally applicable to everyone everywhere in the world and enshrined in international human rights documents. Human rights protect against actions that interfere with fundamental freedoms and human dignity, and support the agency of individuals and populations. The promotion of human rights requires governments and others to take active steps to put in place institutions and procedures that enable people to enjoy their guaranteed rights.
Source: World Health Organization. WHO guideline on self-care interventions for health and well-being, 2022 revision. Geneva: World Health Organization; 2022. https://www.who.int/publications/i/item/9789240052192.

Humidex: The preferred apparent temperature calculation method in Canada. Unlike the heat index, which is used in the US, Humidex (short for “humidity index”) uses dewpoint temperature rather than relative humidity in the calculation (Masterson and Richardson 1979).
Sources:
* Global Heat Health Information Network. GHHIN glossary. https://ghhin.org/glossary/ [Accessed 16th January 2024].
* Gosling SN, Bryce EK, Dixon PG, Gabriel KM, Gosling EY, Hanes JM, et al. A glossary for biometeorology. International Journal of Biometeorology. 2014;58(2): 277–308. doi: 10.1007/s00484-013-0729-9. Epub 2014 Feb 19.

Indirect emissions: Indirect emissions from a building, home or business are those emissions of greenhouse gases that occur as a result of the generation of electricity used in that building. These emissions are called “indirect” because the actual emissions occur at the power plant which generates the electricity, not at the building using the electricity.
Source: United States Environmental Protection Agency. Glossary of Climate Change Terms. https://19january2017snapshot.epa.gov/climatechange/glossary-climate-change-terms_.html#C [Accessed 18th January 2024].

Indoor air quality (IAQ): Indoor air quality refers to the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants.
Source: United States Environmental Protection Agency. Introduction to indoor air quality. https://www.epa.gov/indoor-air-quality-iaq/introduction-indoor-air-quality [Accessed 18th January 2024].

Interpersonal violence: Interpersonal violence refers to violence between individuals, and is subdivided into family and intimate partner violence and community violence. The former category includes child maltreatment; intimate partner violence; and elder abuse, while the latter is broken down into acquaintance and stranger violence and includes youth violence; assault by strangers; violence related to property crimes; and violence in workplaces and other institutions.
Source: World Health Organization. The Violence Prevention Approach. https://www.who.int/groups/violence-prevention-alliance/approach [Accessed 16th January 2024].

Large for gestational age (LGA): A large for gestational age foetus is one whose size is above a predefined threshold for its gestational age. LGA foetuses typically have an estimated foetal weight or abdominal circumference above the 90th percentile.
Source: Salomon LJ, Alfirevic Z, Da Silva Costa F, Deter RL, Figueras F, Ghi T, et al. ISUOG Practice Guidelines: ultrasound assessment of fetal biometry and growth. Ultrasound Obstet Gynecol. 2019;53(6): 715–723. doi: 10.1002/uog.20272. PMID: 31169958.

Low birth weight (LBW): Low birth weight is defined as weight at birth of < 2500 grams (5.5 pounds).
Source: World Health Organization and the United Nations Children’s Fund. UNICEF-WHO Low birthweight estimates: Levels and trends 2000-2015. Geneva: World Health Organization; 2019. https://www.who.int/publications/i/item/WHO-NMH-NHD-19.21.

Malnutrition: Malnutrition refers to deficiencies or excesses in nutrient intake, imbalance of essential nutrients or impaired nutrient utilization. The double burden of malnutrition consists of both undernutrition and overweight and obesity, as well as diet-related noncommunicable diseases. Undernutrition manifests in four broad forms: wasting, stunting, underweight, and micronutrient deficiencies.
Source: World Health Organization. Malnutrition. https://www.who.int/news-room/fact-sheets/detail/malnutrition [Accessed 16th January].

Maternal death (mortality): The death of a woman while pregnant or within 42 days of termination of pregnancy, irrespective of the duration and site of the pregnancy, from any cause related to or aggravated by the pregnancy or its management but not from unintentional or incidental causes.
Source: World Health Organization. Trends in maternal mortality 2000 to 2020: estimates by WHO, UNICEF, UNFPA, World Bank Group and UNDESA/Population Division. Geneva: World Health Organization; 2023. https://www.who.int/publications/i/item/9789240068759.

Maternal morbidity: Maternal morbidity is defined as any health condition attributed to and/or complicating pregnancy, and childbirth that has a negative impact on the woman’s well-being and/or functioning.
Source: World Health Organization. Maternal morbidity and well-being. https://www.who.int/teams/maternal-newborn-child-adolescent-health-and-ageing/maternal-health/maternal-morbidity-and-well-being [Accessed 18th January 2024].

Mean radiant temperature: The mean radiant temperature (Tmrt) is a parameter that combines all longwave and shortwave radiant fluxes to a single value. It is defined as the temperature of a surrounding black body that causes the same radiant heat fluxes as the complex radiant fluxes (Fanger 1972). In human biometeorology Tmrt is usually calculated for a standardised standing person. Since measurements are not available on many operational meteorological stations, different models exist, ranging from simple empirical models to full radiative-transfer models, which allow modelling of radiant fluxes based on standard meteorological measurements.
Sources:
* Global Heat Health Information Network. GHHIN glossary. https://ghhin.org/glossary/ [Accessed 16th January 2024].
* Gosling SN, Bryce EK, Dixon PG, Gabriel KM, Gosling EY, Hanes JM, et al. A glossary for biometeorology. International Journal of Biometeorology. 2014;58(2): 277–308. doi: 10.1007/s00484-013-0729-9. Epub 2014 Feb 19.

Reference:
* Fanger PO. Thermal comfort: Analysis and applications in environmental engineering. New York: McGraw Hill; 1972.

Mental health: A state of mental well-being that enables people to cope with the stresses of life, to realize their abilities, to learn well and work well, and to contribute to their communities. Mental health is an integral component of health and well-being and is more than the absence of mental disorder.
Source: World Health Organization. World mental health report: transforming mental health for all. Geneva: World Health Organization; 2022. https://www.who.int/publications/i/item/9789240049338.

Metabolic rate: Total energy production in a human in unit time, commonly expressed in biometeorological studies based on the total body surface of a human in Wm−2. The standard ISO 8996:2021 outlines the method for the estimation of metabolic heat production.
Sources:
* Global Heat Health Information Network. GHHIN glossary. https://ghhin.org/glossary/ [Accessed 16th January 2024].
* Gosling SN, Bryce EK, Dixon PG, Gabriel KM, Gosling EY, Hanes JM, et al. A glossary for biometeorology. International Journal of Biometeorology. 2014;58(2): 277–308. doi: 10.1007/s00484-013-0729-9. Epub 2014 Feb 19.

Reference:
* International Organization for Standardisation. ISO 8996:2021 Ergonomics of the thermal environment – Determination of metabolic rate. https://www.iso.org/standard/74443.html [Accessed 19th January 2024].

Miscarriage: Miscarriage or spontaneous loss of a pregnancy prior to 24 weeks’ gestation, that is, before the foetus is usually viable outside the uterus. The clinical signs of miscarriage are vaginal bleeding, usually with abdominal pain and cramping. If the pregnancy has been expelled, the miscarriage is termed “complete” or “incomplete” depending on whether or not tissues are retained in the uterus.
Source: World Health Organization. Abortion care guideline. Geneva: World Health Organization; 2022. https://www.who.int/publications/i/item/9789240039483.

Mitigation (measures): A human intervention to reduce emissions or enhance the sinks of greenhouse gases. In climate policy, mitigation measures are technologies, processes or practices that contribute to mitigation, for example, renewable energy (RE) technologies, waste minimization processes and public transport commuting practices.
Source: IPCC. Annex I: Glossary [Matthews JBR (ed.)]. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte V, Zhai P, Pörtner HO, Roberts D, Skea J, Shukla PR, et al. (eds.)]. Cambridge: Cambridge University Press; 2018. doi:10.1017/9781009157940.008.

Neonatal deaths: Neonatal deaths (deaths among live births during the first 28 completed days of life) may be subdivided into early neonatal deaths, occurring during the first seven days of life, and late neonatal deaths, occurring after the seventh day but before 28 completed days of life.
Source: World Health Organization. European Health Information Gateway. https://gateway.euro.who.int/en/indicators/hfa_82-1160-fetal-deaths-per-1000-births/ [Accessed 18th January 2024).

Neonatal period: The neonatal period commences at birth and ends 28 completed days after birth.
Source: World Health Organization. European Health Information Gateway. https://gateway.euro.who.int/en/indicators/hfa_82-1160-fetal-deaths-per-1000-births/ [Accessed 18th January 2024).

Net zero emissions: Net zero emissions are achieved when anthropogenic emissions of greenhouse gases to the atmosphere are balanced by anthropogenic removals over a specified period. Where multiple greenhouse gases are involved, the quantification of net zero emissions depends on the climate metric chosen to compare emissions of different gases (such as global warming potential, global temperature change potential, and others, as well as the chosen time horizon).
Source: IPCC. Annex I: Glossary [Matthews JBR (ed.)]. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte V, Zhai P, Pörtner HO, Roberts D, Skea J, Shukla PR, et al. (eds.)]. Cambridge: Cambridge University Press; 2018. doi:10.1017/9781009157940.008.

Nurturing care: Nurturing care is an environment created by caregivers to ensure children’s good health and nutrition,protect them from threats and give them opportunities for early learning through emotionally supportive, responsive interactions.
Source: World Health Organization and the United Nations Children’s Fund. Investing in our future: a comprehensive agenda for the health and well-being of children and adolescents. Geneva: World Health Organization and the United Nations Children’s Fund; 2021. https://iris.who.int/handle/10665/350239.

Perceived temperature (PT): Perceived temperature is a human biometeorological parameter that describes the thermal perception of an individual, by the use of the air temperature of a reference environment (Staiger et al. 2011). This environment is defined as an indoor room, with the wind velocity reduced to a slight draught, a mean radiant temperature that equals the air temperature, and a water vapour pressure of 50 %. The thermo-physiological modelling is based on the Klima Michel model (KMM).
Sources:
* Global Heat Health Information Network. GHHIN glossary. https://ghhin.org/glossary/ [Accessed 16th January 2024].
* Gosling SN, Bryce EK, Dixon PG, Gabriel KM, Gosling EY, Hanes JM, et al. A glossary for biometeorology. International Journal of Biometeorology. 2014;58(2): 277–308. doi: 10.1007/s00484-013-0729-9. Epub 2014 Feb 19.

Reference:
Staiger H, Laschewski G, Grätz A. The perceived temperature–a versatile index for the assessment of the human thermal environment. Part A: scientific basics. Int J Biometeorol. 2012 Jan;56(1): 165–76. doi: 10.1007/s00484-011-0409-6. Epub 2011 Feb 19. PMID: 21336880.

Perinatal period: The perinatal period commences at 22 completed weeks (154 days) of gestation and ends seven completed days after birth.
Source: World Health Organization. European Health Information Gateway. https://gateway.euro.who.int/en/indicators/hfa_82-1160-fetal-deaths-per-1000-births/ [Accessed 18th January 2024).

Physiological equivalent temperature (PET): Physiological equivalent temperature is a human biometeorological parameter that describes the thermal perception of an individual. It is defined as the air temperature at which, in a typical indoor setting (without wind and solar radiation), the heat budget of the human body is balanced with the same core and skin temperature as under the complex outdoor conditions to be assessed (Höppe 1999). The typical indoor setting is an indoor room, with windspeed (v) = 0.1 ms−1, vapour pressure (VP) = 12 hPa and mean radiant temperature (Tmrt) equal to the air temperature (T_a). For calculating the physiological parameters PET makes use of the Munich energy balance model for individuals (MEMI).
Sources:
* Global Heat Health Information Network. GHHIN glossary. https://ghhin.org/glossary/ [Accessed 16th January 2024].
* Gosling SN, Bryce EK, Dixon PG, Gabriel KM, Gosling EY, Hanes JM, et al. A glossary for biometeorology. International Journal of Biometeorology. 2014;58(2): 277–308. doi: 10.1007/s00484-013-0729-9. Epub 2014 Feb 19.

Reference:
Höppe P. The physiological equivalent temperature – a universal index for the biometeorological assessment of the thermal environment. Int J Biometeorol. 1999;43: 71–75.

Postnatal age: Postnatal age is the age since birth (e.g. an infant born 10 weeks ago at 32 weeks’ gestation is 10 weeks of age/chronological age/postnatal age).
Source: World Health Organization. WHO recommendations for care of the preterm or low birth weight infant. Geneva: World Health Organization; 2022. https://www.who.int/publications/i/item/9789240058262.

Postnatal period: The postnatal period begins immediately after the birth of the baby and extends up to six weeks (42 days) after birth.
Source: World Health Organization. WHO recommendations on maternal and newborn care for a positive postnatal experience. Geneva: World Health Organization; 2022. https://www.who.int/publications/i/item/9789240045989.

Pre-eclampsia: New onset of hypertension (over 140 mmHg systolic or over 90 mmHg diastolic) after 20 weeks of pregnancy and the coexistence of 1 or more of the following new-onset conditions:
-proteinuria (urine protein:creatinine ratio of 30 mg/mmol or more or albumin:creatinine ratio of 8 mg/mmol or more, or at least 1 g/litre [2+] on dipstick testing);
-other maternal organ dysfunction (renal insufficiency, renal involvement, neurological complications, haematological complications);
-uteroplacental dysfunction (including foetal growth restriction, abnormal umbilical artery doppler at ultrasound, stillbirth).
Source: National Institute for Health and Care Excellence (NICE), Hypertension in pregnancy: diagnosis and management: NICE guideline [NG133]. 2023. https://www.nice.org.uk/guidance/NG133 [Accessed 18th January 2024].

Pre-industrial level: The global temperature level before the Industrial Revolution (approximately mid-19th century). The multi-century period prior to the onset of largescale industrial activity around 1750. The reference period 1850–1900 is used to approximate pre-industrial global mean surface temperature.
Source: IPCC. Annex I: Glossary [Matthews JBR (ed.)]. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte V, Zhai P, Pörtner HO, Roberts D, Skea J, Shukla PR, et al. (eds.)]. Cambridge: Cambridge University Press; 2018. doi:10.1017/9781009157940.008.

Predicted heat strain: ISO 7933 describes a procedure for analytical evaluation and interpretation of thermal stress experienced by a person in a hot environment (ISO 7933-2023). Based on a comprehensive model of the heat transfer between the body and surroundings, the procedure evaluates thermal strain by excessive core temperature increase or water loss for a standard subject. In addition, the procedure allows determination of the exposure time during which the physiological strain is acceptable. As the procedure predicts physiological strain for standard persons it needs to be adapted if it should be used to assess thermal strain among vulnerable populations.
Source: International Organization for Standardization. ISO 7933:2023 – Ergonomics of the thermal environment. Analytical determination and interpretation of heat stress using calculation of the predicted heat strain. https://www.iso.org/standard/78240.html [Accessed 16th January 2024].

Prelacteal feeding: Prelacteal feeding is defined as any fluid given to a child before breastfeeding starts.
Source: World Health Organization. Guideline: protecting, promoting and supporting breastfeeding in facilities providing maternity and newborn services. Geneva: World Health Organization; 2017. https://www.who.int/publications/i/item/9789241550086.

Premature rupture of membranes (PROM): Premature rupture of membranes is the rupture of gestational membranes prior to the onset of labour. When membrane rupture occurs before 37 weeks of gestation, it is referred to as preterm PROM (pPROM).
Source: National Institute for Health and Care Excellence (NICE), Intrapartum care for healthy women and babies. Clinical guideline [CG190]. 2022. https://www.nice.org.uk/guidance/cg190 [Accessed 18th January 2024].

Preterm birth: Preterm is defined as babies born alive before 37 weeks of pregnancy are completed. There are sub-categories of preterm birth, based on gestational age:
*extremely preterm (less than 28 weeks)
*very preterm (28 to 32 weeks)
moderate to late preterm (32 to 37 weeks).
Source: World Health Organization. WHO recommendations for care of the preterm or low birth weight infant. Geneva: World Health Organization; 2022. https://www.who.int/publications/i/item/9789240058262.

Primary health care (PHC): Primary health care is an overall approach to the organization of health systems which encompasses the three aspects of: multisectoral policy and action to address the broader determinants of health; empowering individuals, families and communities; and meeting people’s essential health needs throughout their lives.
Source: World Health Organization. Health promotion glossary of terms 2021. Geneva: World Health Organization; 2021. https://www.who.int/publications/i/item/9789240038349.

Quality of care (QoC): Quality of care encompasses six areas or dimensions of quality that are required in relation to health care:
(1) effective, delivering health care that is adherent to an evidence base and results in improved health outcomes for individuals and communities, based on need;
(2) efficient, delivering health care in a manner which optimizes resource use and avoids waste;
(3) accessible, delivering health care that is timely, geographically reachable, and provided in a setting where skills and resources are appropriate to medical need;
(4) acceptable/person-centred, delivering health care that takes into account the preferences and aspirations of individual service users and the cultures of their communities;
(5) equitable, delivering health care that does not vary in quality because of personal characteristics such as gender, race, ethnicity, geographical location or socioeconomic status;
(6) safe, delivering health care that minimizes risks and harm to service users.
Source: World Health Organization. Abortion care guideline. Geneva: World Health Organization; 2022. https://www.who.int/publications/i/item/9789240039483.

Resilience: Resilience is the capacity of a social-ecological system to cope with a hazardous event or disturbance, responding or reorganizing in ways that maintain its essential function, identity and structure, while also maintaining the capacity for adaptation, learning and transformation.
Source: World Health Organization. Operational framework for building climate resilient health systems. Geneva: World Health Organization; 2015. https://www.who.int/publications-detail-redirect/9789241565073.

Risk: The potential for adverse consequences where something of value is at stake and where the occurrence and degree of an outcome is uncertain. In the context of the assessment of climate impacts, the term risk is often used to refer to the potential for adverse consequences of a climate-related hazard, or of adaptation or mitigation responses to such a hazard, on lives, livelihoods, health and well-being, ecosystems and species, economic, social and cultural assets, services (including ecosystem services), and infrastructure. Risk results from the interaction of vulnerability (of the affected system), its exposure over time (to the hazard), as well as the (climate-related) hazard and the likelihood of its occurrence.
Source: IPCC. Annex I: Glossary [Matthews JBR (ed.)]. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte V, Zhai P, Pörtner HO, Roberts D, Skea J, Shukla PR, et al. (eds.)]. Cambridge: Cambridge University Press; 2018. doi:10.1017/9781009157940.008.

Risk factor: Risk factors are social, economic or biological status, behaviours or environments which are associated with or cause increased susceptibility to a specific disease, ill health, or injury.
Source: World Health Organization. Health promotion glossary of terms 2021. Geneva: World Health Organization; 2021. https://www.who.int/publications/i/item/9789240038349.

Self-care: Self-care is the ability of individuals, families and communities to promote health, prevent disease, maintain health and cope with illness and disability with or without the support of a health worker.
Source: World Health Organization. WHO guideline on self-care interventions for health and well-being, 2022 revision. Geneva: World Health Organization; 2022. https://www.who.int/publications/i/item/9789240052192.

Small for gestational age (SGA): Small for gestational age is defined as a birth weight of less than 10th percentile for gestational age.
Source: World Health Organization. WHO recommendations for care of the preterm or low birth weight infant. Geneva: World Health Organization; 2022. https://www.who.int/publications/i/item/9789240058262.

Social value of mitigation activities (SVMA): Social, economic and environmental value of mitigation activities that include, in addition to their climate benefits, their co-benefits to adaptation and sustainable development objectives.
Source: IPCC. Annex I: Glossary [Matthews JBR (ed.)]. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte V, Zhai P, Pörtner HO, Roberts D, Skea J, Shukla PR, et al. (eds.)]. Cambridge: Cambridge University Press; 2018. doi:10.1017/9781009157940.008.

Spontaneous abortion: Miscarriage or spontaneous loss of a pregnancy, prior to 24 weeks’ gestation, that is, before the foetus is usually viable outside the uterus. The clinical signs of miscarriage are vaginal bleeding, usually with abdominal pain and cramping. If the pregnancy has been expelled, the miscarriage is termed “complete” or “incomplete” depending on whether or not tissues are retained in the uterus.
Source: World Health Organization. Abortion care guideline. Geneva: World Health Organization; 2022. https://www.who.int/publications/i/item/9789240039483.

Stillbirth: A baby who dies after 28 weeks of pregnancy, but before or during birth, is classified as a stillbirth.
Source: World Health Organization. Stillbirth. https://www.who.int/health-topics/stillbirth#tab=tab_1 [Accessed 16th January 2024].

Stress: Stress can be defined as a state of worry or mental tension caused by a difficult situation. Stress is a natural human response that prompts us to address challenges and threats in our lives.
Source: World Health Organization. Stress. https://www.who.int/news-room/questions-and-answers/item/stress [Accessed 18th January 2024].

Stunting: Stunting is defined as length-for-age z score less than 2 standard deviation scores below the WHO child growth standards median.
Source: World Health Organization. Child growth standards. https://www.who.int/tools/child-growth-standards/standards [Accessed 18th January 2024].

Sustainable Development Goal (SDG): The Sustainable Development Goals are a call for action by all countries – developed and developing – in a global partnership. They recognize that ending poverty and other deprivations must go hand-in-hand with strategies that improve health and education, reduce inequality, and spur economic growth – all while tackling climate change and working to preserve our oceans and forests.
Source: World Health Organization. Health promotion glossary of terms 2021. Geneva: World Health Organization; 2021. https://www.who.int/publications/i/item/9789240038349.

Temperature anomaly: The difference between the current global average temperature and the global average temperature for pre-industrial levels from 1700s or a climatology period of 30 years commonly 1981 to 2010 or 1991 to 2020.
Source: National Centres for Environmental Information. Anomalies vs. Temperature. https://www.ncei.noaa.gov/access/monitoring/dyk/anomalies-vs-temperature [Accessed 18th January 2024].

Thermal comfort: Thermal comfort is the condition of mind that expresses satisfaction with the thermal environment; however, due to large physiological and psychological variations from one person to another, it is difficult to maintain thermal comfort in one given space for all (ASHRAE 2004), whether it be indoors or outdoors. It is crucial for human beings to maintain a constant core body temperature of 37 °C (98 °F). However, the temperature away from the core, such as on the skin and extremities for instance, can vary considerably with environmental and metabolic heat loads. To maintain the core body temperature, heat is exchanged with the environment by respiration (latent and sensible heat fluxes), radiation (longwave and shortwave), evaporation (latent heat flux), conduction (contact with solids), and convection (sensible heat flux) (Jendritzky and de Dear 2009). To this end, the human thermoregulatory system can be separated into active and passive interacting systems. The active system concerns the thermoregulatory response (e.g. shivering or perspiring) and the passive system deals with heat transfers at the body surface. When the body is under thermal comfort conditions, the body is under least strain because the active system is at its lowest activity level. However, increasing discomfort is associated with increasing strain. Research shows that people take action to improve their comfort conditions by modifying their clothing and metabolic rate when outdoors, or by interacting with the building when they are indoors, which are considered actions of adaptation (Nicol and Humphreys 2002). When adaptation opportunity is limited, departure from neutrality causes stress and dissatisfaction (Baker and Standeven 1996). According to Nikolopoulou et al. (2001), intrinsic factors such as past experience, expectations and time of exposure are also important for thermal comfort.
Sources:
* Global Heat Health Information Network. GHHIN glossary. https://ghhin.org/glossary/ [Accessed 16th January 2024].
* Gosling SN, Bryce EK, Dixon PG, Gabriel KM, Gosling EY, Hanes JM, et al. A glossary for biometeorology. International Journal of Biometeorology. 2014;58(2): 277–308. doi: 10.1007/s00484-013-0729-9. Epub 2014 Feb 19.

References:
* ASHRAE. ASHRAE Standard, ANSI/ASHRAE Standard 55-2004: thermal environmental conditions for human occupancy. Atlanta, GA: American Society of Heating, Refrigerating, and Air-Conditioning Engineers; 2004.
* Jendritzky G, de Dear R. Adaptation and thermal environment. In: Ebi KL, Burton I, McGregor GR. (eds.) Biometeorology for adaptation to climate variability and change, vol 1. Biometeorology. Netherlands: Springer; 2009. p. 9–32.
* Nicol JF, Humphreys MA. Adaptive thermal comfort and sustainable thermal standards for buildings. Energy Build. 2002;34: 563–572.
* Baker N, Standeven M. Thermal comfort for free-running buildings. Energy Build. 1996;23: 175–182.
* Nikolopoulou M, Baker N, Steemers K. Thermal comfort in outdoor urban spaces: understanding the human parameter. Sol Energy. 2001;70: 227–235.

Thermal insulation of clothing: For healthcare workers participating in the time-motion study, the clothing thermal insulation will be estimated with a short tick-off questionnaire reflecting the garments worn by the HCW (Appendix 7 Clothing questionnaire). Based on tabulated values of garment insulation values, the intrinsic clothing insulation will be estimated (ISO 9920-2009). Water vapour permeability of the clothing will be estimated at standard value of 0.45, unless particularly non-permeable garments are worn (apron or similar) (ISO 9920-2009).
Source: International Organization for Standardization. ISO 15831:2004. Clothing – Physiological effects – Measurement of thermal insulation by means of a thermal manikin. https://www.iso.org/standard/28720.html [Accessed 16th January 2024].

Thermal stress: In hot environments and/or during increased physical activity, the body may not be able to effectively dissipate metabolic heat. This situation can ultimately lead to increased core body temperature and diminished physical and mental abilities. Heat exhaustion and heat stroke are also possible side effects of sustained elevated body temperature. In extreme cases thermal stress can directly lead to human mortality. There are numerous quantitative indices for assessing potential thermal stress, including the Heat Stress Index (HSI), the Wet Bulb Globe Temperature (WBGT), the Index of Heat Stress, the Physiological Equivalent Temperature (PET), the Universal Thermal Climate Index (UTCI) and the Humidex.
Sources:
* Global Heat Health Information Network. GHHIN glossary. https://ghhin.org/glossary/ [Accessed 16th January 2024].
* Gosling SN, Bryce EK, Dixon PG, Gabriel KM, Gosling EY, Hanes JM, et al. A glossary for biometeorology. International Journal of Biometeorology. 2014;58(2): 277–308. doi: 10.1007/s00484-013-0729-9. Epub 2014 Feb 19.

Thermoneutral zone (TNZ): When no responses by the body are initiated in response to the external environment and the core temperature can be maintained between 36 to 37.5°C this is known as the thermoneutral zone.
Source: Mekjavic IB, Eiken O. Contribution of thermal and nonthermal factors to the regulation of body temperature in humans. J Appl Physiol. 2006;100(6): 2065–72. doi: 10.1152/japplphysiol.01118.2005. Epub 2006 Jan 12. PMID: 16410380.

Threshold temperature: Temperature above or below at which significant elevations in morbidity or mortality are observed. In the case of heat-related mortality, methods for establishment of threshold temperatures include identification of an inflection point in the “J-shaped” or “U-shaped” relationship between temperature and mortality (Gosling et al. 2007), or a certain percentile of temperature associated with statistically significant increases in risk of mortality (Basu 2009). Threshold temperatures systematically vary geographically, such that those regularly exposed to high temperatures are less susceptible to heat than those that live in cooler locales (e.g. Davis et al. 2002).
Sources:
* Global Heat Health Information Network. GHHIN glossary. https://ghhin.org/glossary/ [Accessed 16th January 2024].
* Gosling SN, Bryce EK, Dixon PG, Gabriel KM, Gosling EY, Hanes JM, et al. A glossary for biometeorology. International Journal of Biometeorology. 2014;58(2): 277–308. doi: 10.1007/s00484-013-0729-9. Epub 2014 Feb 19.
* Honda Y, Kondo M, McGregor G, Kim H, Guo YL, Hijioka Y, et al. Heat-related mortality risk model for climate change impact projection. Environ Health Prev Med. 2014;19(1): 56–63. doi: 10.1007/s12199-013-0354-6. Epub 2013 Aug 9. PMID: 23928946; PMCID: PMC3890078.

References:
* Basu R. High ambient temperature and mortality: a review of epidemiologic studies from 2001 to 2008. Environ Heal. 2009;8: 1–13.
* Davis RE, Knappenberger PC, Novicoff WM, Michaels PJ. Decadal changes in heat-related human mortality in the eastern United States. Clim Res. 2002;22: 175–184.

Tipping point: A level of change in system properties beyond which a system reorganizes, often abruptly, and does not return to the initial state even if the drivers of the change are abated. For the climate system, it refers to a critical threshold when global or regional climate changes from one stable state to another stable state.
Source: IPCC. Annex I: Glossary [Matthews JBR (ed.)]. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte V, Zhai P, Pörtner HO, Roberts D, Skea J, Shukla PR, et al. (eds.)]. Cambridge: Cambridge University Press; 2018. doi:10.1017/9781009157940.008.

Tropical nights: Daily minimum 2m air temperature over 20°C; Unit: No. Nights.
Source: Fontaine B, Janicot S, Monerie PA. Recent changes in air temperature, heat waves occurrences and atmospheric circulation in Northern Africa. J. Geophys. Res. Atmos. 2013;118: 8536–8552. doi:10.1002/jgrd.50667.

Undernutrition: Undernutrition manifests in four broad forms: wasting, stunting, underweight, and micronutrient deficiencies.
Malnutrition refers to deficiencies or excesses in nutrient intake, imbalance of essential nutrients or impaired nutrient utilization. The double burden of malnutrition consists of both undernutrition and overweight and obesity, as well as diet-related noncommunicable diseases.
Source: World Health Organization. Malnutrition. https://www.who.int/news-room/fact-sheets/detail/malnutrition [Accessed 16th January 2024].

Underweight: Underweight is defined as weight-for-age z score less than 2 standard deviation scores below the WHO child growth standards median.
Source: World Health Organization. Child growth standards. https://www.who.int/tools/child-growth-standards/standards [Accessed 18th January 2024].

Universal health coverage (UHC): Universal health coverage means that all people have access to the health services they need, at high quality, when and where they need them, without financial hardship across the life course. It includes the full range of essential health services, from health promotion to prevention, treatment, rehabilitation and palliative care.
Source: World Health Organization. Health promotion glossary of terms 2021. Geneva: World Health Organization; 2021. https://www.who.int/publications/i/item/9789240038349.

Universal thermal climate index (UTCI): The universal thermal climate index is a bioclimatological model of an average human body’s response to different thermal conditions where the subject is not acclimatised to the climate and is outdoors, doing minimal work (Bröde et al., 2012; di Napoli et al., 2018; Fiala et al., 2012). It was developed as part of the COST European Cooperation in Scientific and Technical Research action 370 in the early 2000s.
Most research uses a 6-order polynomial that is an approximation of a more complicated body model (Brimicombe et al., 2022; Bröde et al., 2012). The input variables are air temperature, dew point temperature, mean radiant temperature and wind speed (m/s).
Source: Brimicombe C. Too Hot to Handle: The Global Impact of Extreme Heat. 2022. doi:10.48683/1926.00113452.

References:
* Bröde P, Fiala D, Błażejczyk K, Holmér I, Jendritzky G, Kampmann B, et al. Deriving the operational procedure for the Universal Thermal Climate Index (UTCI). International Journal of Biometeorology. 2012;56(3): 481–494. doi:10.1007/s00484-011-0454-1.
* Di Napoli C, Pappenberger F, Cloke HL. Assessing heat-related health risk in Europe via the Universal Thermal Climate Index (UTCI). International Journal of Biometeorology. 2018; 62(7): 1155–1165. doi:10.1007/s00484-018-1518-2.
* Fiala D, Havenith G, Bröde P, Kampmann B, Jendritzky G. UTCI-Fiala multi-node model of human heat transfer and temperature regulation. International Journal of Biometeorology. 2012;56(3): 429–441. doi:10.1007/s00484-011-0424.
* Brimicombe C, Quintino T, Smart S, Di Napoli C, Hogan R, Cloke HL, Pappenberger F. Calculating the Cosine of the Solar Zenith Angle for Thermal Comfort Indices. 2022. doi:10.21957/o7pcu1x2b.

Usability: Usability is the extent to which a system, product or service can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use.
Source: International Organization for Standardardization. ISO 9241-11:2018 Ergonomics of human-system interaction – Part 11: Usability: Definitions and concepts. https://www.iso.org/standard/63500.html [Accessed 22nd January 2024.

Very low birth weight (VLBW): Very low birth weight is birth weight below 1.5 kg (regardless of gestational age).
Source: World Health Organization. WHO recommendations for care of the preterm or low birth weight infant. Geneva: World Health Organization; 2022. https://www.who.int/publications/i/item/9789240058262.

Vulnerable populations: Groups of people who are particularly vulnerable to health conditions in certain situations or contexts, due to socioeconomic factors, disabilities, legal status and/or unequal power dynamics. WHO defines vulnerability as the degree to which a population, individual or organization is unable to anticipate, cope with, resist or recover from the impacts of disasters. Vulnerable populations can include children, pregnant individuals, elderly people, malnourished people and those who are ill or immunocompromised.
Source: World Health Organization. WHO guideline on self-care interventions for health and well-being, 2022 revision. Geneva: World Health Organization; 2022. https://www.who.int/publications/i/item/9789240052192.

Wasting: Wasting is defined as the weight-for-length z score less than 2 standard deviation scores below the WHO child growth standards median.
Source: World Health Organization. Child growth standards. https://www.who.int/tools/child-growth-standards/standards [Accessed 18th January 2024].

Well-being: Well-being is a positive state experienced by individuals and societies. Similar to health, it is a resource for daily life and is determined by social, economic and environmental conditions.
Source: World Health Organization. Health promotion glossary of terms 2021. Geneva: World Health Organization; 2021. https://www.who.int/publications/i/item/9789240038349.

Wet Bulb Globe Temperature (WBGT): Wet Bulb Globe Temperature is the most widely used heat index because it is an international standard for heat stress (Budd, 2008; Buzan et al., 2015). It was originally developed in the 1950s as part of a campaign to lower the risk of heat disorders during the training of US Army and Marine troops.
Wet bulb globe temperature is calculated using observations from a wet bulb thermometer – a thermometer wrapped in a damp muslin cloth, a globe thermometer to measure incidence of radiation and a dry air thermometer. Or it is approximated using empirical models of these values (Davies-Jones, 2008; Liljegren et al., 2008; Stull, 2011).
The equation for an outdoor WBGT is: WBGT=0.7T_w+0.2T_g+0.1T_d
The equation for an indoor WBGT is: WBGT=0.7T_w+0.3T_g
Where T_w is Wet Bulb Temperature (°C), T_g is Globe Temperature (°C) and T_d is air temperature (°C).
Source: Brimicombe C. Too Hot to Handle: The Global Impact of Extreme Heat. 2022. doi:10.48683/1926.00113452.

References:
* Budd GM. Wet-bulb globe temperature (WBGT) – its history and its limitations. J Sci Med Sport. 2008;11(1): 20–32. doi:10.1016/j.jsams.2007.07.003. Epub 2007 Aug 31. PMID: 17765661.
* Buzan JR, Oleson K, Huber M. Implementation and comparison of a suite of heat stress metrics within the Community Land Model version 4.5. Geoscientific Model Development. 2015;8(2): 151–170. doi:10.5194/gmd-8-151-2015.
* Davies-Jones R. An efficient and accurate method for computing the wet‐bulb temperature along pseudoadiabats. Monthly Weather Review. 2008;136(7): 2764–2785. doi:10.1175/2007MWR2224.1.
* International Organization for Standardisation. ISO 7243:2017 Ergonomics of the thermal environment – Assessment of heat stress using the WBGT (wet bulb globe temperature) index. https://www.iso.org/standard/67188.html [Accessed 16th January 2024].
* Minard D. Prevention of heat casualties in Marine Corps recruits. Period of 1955-60, with comparative incidence rates and climatic heat stresses in other training categories. Military Medicine. 1961;126(4): 261–272. doi:10.1093/milmed/126.4.261.
* Liljegren JC, Carhart RA, Lawday P, Tschopp S, Sharp R. Modeling the wet bulb globe temperature using standard meteorological measurements. Journal of Occupational and Environmental Hygiene. 2008;5(10): 645–655. doi:10.1080/15459620802310770.
* Stull R. Wet-Bulb Temperature from Relative Humidity and Air Temperature. Journal of Applied Meteorology and Climatology. 2011;50(11): 2267–2269. doi:10.1175/JAMC-D-11-0143.7.