Editing Heat wave (section)

== Impacts on human health ==
[[File:Heat stroke treatment, Baton Rouge, 2016 Louisiana floods.jpg|thumb|[[Heat stroke]] treatment at Baton Rouge during the [[2016 Louisiana floods]]]]

=== Heat-related health effects for vulnerable humans ===
{{excerpt|heat illness|paragraphs=1-2|file=no}}

{{excerpt|Effects of climate change on human health#Heat-related health effects for vulnerable people|paragraphs=1-2|file=no}}

=== Mortality ===
[[File:NWS HeatRisk Categories.jpg|thumb|The National Weather Service risk categories for ''NWS HeatRisk'']]
{{excerpt|Effects of climate change on human health#Heat-related mortality|paragraphs=1-2|file=no}}

==== Underreporting of fatalities ====
The number of heat fatalities is probably highly underreported. This is due to a lack of reports and to misreporting.<ref name="heat epidemiology">{{cite journal |last=Basu |first=Rupa |author2=Jonathan M. Samet |year=2002 |title=Relation between Elevated Ambient Temperature and Mortality: A Review of the Epidemiologic Evidence |journal=[[Epidemiologic Reviews]] |volume=24 |issue=2 |pages=190–202 |doi=10.1093/epirev/mxf007 |pmid=12762092 |doi-access=free}}</ref> When considering heat-related illnesses as well, actual death tolls from extreme heat may be six times higher than official figures. This is based on studies of California<ref>{{Cite web |title=Heat waves are far deadlier than we think. How California neglects this climate threat |url=https://www.latimes.com/projects/california-extreme-heat-deaths-show-climate-change-risks/ |access-date=2022-09-04 |website=Los Angeles Times |date=7 October 2021 |language=en}}</ref> and Japan.<ref>{{Cite journal |last1=Fujibe |first1=Fumiaki |last2=Matsumoto |first2=Jun |date=2021 |title=Estimation of Excess Deaths during Hot Summers in Japan |url=https://www.jstage.jst.go.jp/article/sola/17/0/17_2021-038/_article/-char/ja |journal=Scientific Online Letters on the Atmosphere |volume=17 |pages=220–223 |bibcode=2021SOLA...17..220F |doi=10.2151/sola.2021-038 |s2cid=241577645 |doi-access=free}}</ref>

Part of the mortality during a heat wave may be due to short-term forward [[mortality displacement]]. In some heat waves there is a decrease in overall mortality in the weeks after a heat wave. These compensatory reductions in mortality suggest that heat affects people who would have died anyway, and brings their deaths forward.<ref name="pmid11401757">{{cite journal |last1=Huynen |first1=Maud M. T. E |last2=Martens |first2=Pim |last3=Schram |first3=Dieneke |last4=Weijenberg |first4=Matty P |last5=Kunst |first5=Anton E |year=2001 |title=The Impact of Heat Waves and Cold Spells on Mortality Rates in the Dutch Population |journal=Environmental Health Perspectives |volume=109 |issue=5 |pages=463–70 |doi=10.2307/3454704 |jstor=3454704 |pmc=1240305 |pmid=11401757}}</ref>

Social institutions and structures influence the effects of risks. This factor can also help explain the underreporting of heat waves as a health risk. The deadly [[2003 European heat wave#France|French heat wave]] in 2003 showed that heat wave dangers result from a combination of natural and social factors.<ref>{{cite journal |last1=Poumadère |first1=M. |last2=Mays |first2=C. |last3=Le Mer |first3=S. |last4=Blong |first4=R. |year=2005 |title=The 2003 Heat Wave in France: Dangerous Climate Change Here and Now |url=http://www.coe.int/t/dg4/majorhazards/activites/murcia_26-27oct2009/heatwave2003_poumadere2005.pdf |journal=Risk Analysis |volume=25 |issue=6 |pages=1483–1494 |citeseerx=10.1.1.577.825 |doi=10.1111/j.1539-6924.2005.00694.x |pmid=16506977 |bibcode=2005RiskA..25.1483P |s2cid=25784074}}</ref> Social invisibility is one such factor. Heat-related deaths can occur indoors, for instance among elderly people living alone. In these cases it can be challenging to assign heat as a contributing factor.<ref>{{Cite journal |last=Ro |first=Christine |date=2022-09-01 |title=Can Japan really reach "zero deaths" from heat stroke? |url=https://www.bmj.com/content/378/bmj.o2107 |journal=BMJ |language=en |volume=378 |pages=o2107 |doi=10.1136/bmj.o2107 |issn=1756-1833 |s2cid=251954370 |doi-access=free|url-access=subscription }}</ref>

=== Heat index for temperature and relative humidity ===
{{HeatTable}}
The [[heat index]] in the table above is a measure of how hot it feels when relative humidity is factored with the actual air temperature.

=== Psychological and sociological effects ===
Excessive heat causes psychological stress as well as physical [[stress (biology)|stress]]. This can affect performance. It may also lead to an increase in violent crime.<ref name="heat and stress">{{cite journal |last=Simister |first=John |author2=Cary Cooper |title=Thermal stress in the U.S.A.: effects on violence and on employee behaviour |journal=Stress and Health |volume=21 |issue=1 |pages=3–15 |date=October 2004 |doi=10.1002/smi.1029 |doi-access=free }}</ref> High temperatures are associated with increased conflict between individuals and at the social level. In every society, [[crime]] rates go up when temperatures go up. This is particularly the case with violent crimes such as assault, murder and rape. In politically unstable countries, high temperatures can exacerbate factors that lead to civil war.<ref>{{cite journal |last1=Hsiang |first1=Solomon |last2=Burke |first2=Marshall |last3=Miguel |first3=Edward |title=Climate and Conflict |journal=Annual Review of Economics |volume=7 |issue=1 |pages=577–617 |year=2015 |doi=10.1146/annurev-economics-080614-115430 |s2cid=17657019 }}</ref>

High temperatures also have a significant effect on income. A study of countries in the United States found that the economic productivity of individual days declines by about 1.7 percent for each degree Celsius above {{convert|15|°C|°F}}.<ref>{{cite journal |last1=Solomon |first1=Hsiang |last2=Tatyana |first2=Deryugina |title=Does the Environment Still Matter? Daily Temperature and Income in the United States |journal=NBER Working Paper No. 20750 |date=December 2014 |doi=10.3386/w20750 |doi-access=free }}</ref>

=== Surface ozone (air pollution) ===
{{Further|Ozone#Ozone air pollution|Ozone#Low level ozone in urban areas}}High temperatures also make the effects of [[ozone]] pollution in urban areas worse. This raises heat-related mortality during heat waves.<ref>{{Cite journal |last1=Diem |first1=Jeremy E. |last2=Stauber |first2=Christine E. |last3=Rothenberg |first3=Richard |date=2017-05-16 |editor-last=Añel |editor-first=Juan A. |title=Heat in the southeastern United States: Characteristics, trends, and potential health impact |journal=PLOS ONE |volume=12 |issue=5 |pages=e0177937 |bibcode=2017PLoSO..1277937D |doi=10.1371/journal.pone.0177937 |issn=1932-6203 |pmc=5433771 |pmid=28520817 |doi-access=free}}</ref> During heat waves in urban areas, ground level ozone pollution can be 20 percent higher than usual.<ref>{{Cite journal |last1=Hou |first1=Pei |last2=Wu |first2=Shiliang |date=July 2016 |title=Long-term Changes in Extreme Air Pollution Meteorology and the Implications for Air Quality |journal=Scientific Reports |volume=6 |issue=1 |pages=23792 |bibcode=2016NatSR...623792H |doi=10.1038/srep23792 |issn=2045-2322 |pmc=4815017 |pmid=27029386}}</ref>

One study looked at fine particle concentrations and ozone concentrations from 1860 to 2000. It found that the global population-weighted fine particle concentrations increased by 5 percent due to climate change. Near-surface ozone concentrations rose by 2 percent.<ref>{{Cite journal |last1=Orru |first1=H. |last2=Ebi |first2=K. L. |last3=Forsberg |first3=B. |date=2017 |title=The Interplay of Climate Change and Air Pollution on Health |journal=Current Environmental Health Reports |volume=4 |issue=4 |pages=504–513 |doi=10.1007/s40572-017-0168-6 |issn=2196-5412 |pmc=5676805 |pmid=29080073|bibcode=2017CEHR....4..504O }}</ref>

An investigation to assess the joint mortality effects of ozone and heat during the European heat waves in 2003 concluded that these appear to be additive.<ref>{{cite journal |author=Kosatsky T. |date=July 2005 |title=The 2003 European heat waves |url=http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=552 |journal=Eurosurveillance |volume=10 |issue=7 |pages=3–4 |doi=10.2807/esm.10.07.00552-en |pmid=29208081 |access-date=14 January 2014 |doi-access=free}}</ref>