Effects of high temperatures on human health
Pro Research Analysisby 
Searched over 200M research papers
High Temperatures and Heat-Related Illnesses
High temperatures and heatwaves are strongly linked to an increase in heat-related illnesses and deaths. For every 1°C rise above local baseline temperatures, the risk of direct heat illness rises by 18%, and the risk of death from heat-related causes increases by 35%. The most significant increases are seen in direct heat illnesses, such as heat stroke, compared to other conditions like dehydration. Older adults, especially those over 65, and people living in subtropical climates are particularly vulnerableFaurie2022Green2019.
Mortality, Morbidity, and Vulnerable Populations
Numerous studies confirm that high temperatures and heatwaves lead to more hospitalizations and deaths, especially among the elderly, women, people with lower socioeconomic status, and those with pre-existing health conditionsEbi2021Kunda2024Yang2022+2 MORE. In low- and middle-income countries, the impact is often more severe due to limited resources for adaptation and healthcareKunda2024Green2019. Urban areas can experience even higher temperatures due to heat from vehicles and buildings, further increasing health risks.
Effects on Mental Health and Well-Being
High temperatures also negatively affect mental health, increasing the likelihood of depression, especially among the middle-aged, elderly, women, less-educated individuals, and agricultural workersKunda2024Hua2022. Heat can worsen mental health in low-income adults and reduce overall well-being and social comfort, particularly for those working outdoorsKunda2024Yang2022Hua2022. Mechanisms include increased physical illness and reduced sleep during hot periods.
Impact on Workers and Occupational Health
Workers exposed to high temperatures, such as those in agriculture, construction, and other outdoor jobs, face higher risks of heat-related illnesses, kidney disease, and occupational injuriesEbi2021Kunda2024Yang2022+1 MORE. High heat also reduces physical work capacity and productivity, with the most severe effects seen in those performing heavy manual labor outdoorsEbi2021Kunda2024Revich2025. These risks are especially pronounced during heatwaves and in regions with extreme temperaturesKunda2024Revich2025.
Cardiovascular and Endocrine Health Risks
High temperatures are associated with increased deaths from cardiovascular diseases, including heart attacks and strokesBan2017Li2024. Heat can trigger myocardial injury and heart failure due to the body’s natural sweating and cooling mechanisms. There is also growing concern about the effects of heat on the endocrine system, which regulates the body’s response to temperature changes. People with hormone-related diseases may be at higher risk of heat injury, but more research is needed in this area.
Social Inequalities and Adaptation
Social inequalities play a significant role in heat exposure and health outcomes. Rural residents, people with lower education, and those with fewer resources are more likely to suffer from the effects of high temperaturesKunda2024Yang2022Green2019. While some adaptation is occurring in high-income countries, the overall risk of heat-related illness and death is expected to rise as climate change leads to more frequent and intense heatwavesEbi2021Green2019Hua2022.
Conclusion
High temperatures have wide-ranging and serious effects on human health, increasing the risk of heat-related illnesses, deaths, mental health problems, and occupational injuries. Vulnerable groups—including the elderly, outdoor workers, and those with fewer resources—are at greatest risk. As climate change continues to drive up global temperatures, targeted public health interventions and adaptation strategies are urgently needed to protect the most affected populationsFaurie2022Ebi2021Kunda2024+7 MORE.
Sources and full results
Most relevant research papers on this topic