The changing climate has a profound impact on current weather conditions. Currently, Heidelberg and Europe in general are experiencing extremely hot weather with average temperatures between 26 and 32 degrees, with multiple warnings of waves that can take temperatures up to 37 or above. The hot weather is affecting all aspects of health and well-being, with more harmful effects on vulnerable populations, affecting mental health and behaviours, decreased productivity, sleep loss, and increased disease risks.
The Lancet Countdown on health and climate change in Europe report 2026 systematically tracks the health effects of heat, drawing on data up to 2025.
Health and economic impacts of heat are increasing every year- deaths, lack of safety, food insecurity and reduced labour supply
The Lancet report shows that heat is having a much greater impact on health across Europe. Compared with 1991–2000, almost every region experienced more heat-related deaths during 2015–24. Daily extreme heat warnings also increased by 318%. Heat exposure among infants and adults aged 65 and older rose by 1.17 billion person-days (254%), while the number of hours when it was too hot to safely do light or moderate physical activity increased by 88%. In 2023, more than 1 million extra people faced moderate or severe food insecurity because of more frequent heatwaves and droughts. Rising temperatures also reduced the average labour supply by about 24 hours per worker each year during 2000–23 compared with 1965–94.
Increased risk to infectious diseases
Climate change is increasing the risk of infectious diseases in Europe by creating more favourable conditions for disease-carrying insects and other vectors. Between 2015 and 2024, the climate became 297% more suitable for dengue virus transmission compared with 1981–2010, contributing to more outbreaks. Climate change has also lengthened the pollen season by 1–2 weeks, meaning people with hay fever and other pollen allergies are exposed to allergens for longer.
The health impacts of climate change are not shared equally
The health impacts of climate change are not shared equally. Low-income households are more likely to experience food insecurity because of increasing heatwaves and droughts than middle-income households. Outdoor workers, particularly in construction and agriculture, face a higher risk of heat-related illness and injury. People living in poorer regions are also more exposed to wildfires and often have less access to green spaces, which can help reduce the effects of extreme heat. The Lancet report points out that although more European countries have introduced national climate adaptation plans and climate services for the health sector, these measures need to better address the needs of the groups most vulnerable to climate change.
Exposure of at-risk populations to heatwaves
The summer of 2024 was the hottest ever recorded in Europe, with many areas experiencing long periods of extreme heat. Heatwaves are especially dangerous for babies under 1 year old and adults aged 65 and older. In 2024, these high-risk groups experienced 2.3 billion person-days of heatwave exposure-the highest ever recorded, surpassing the previous record of 2.1 billion person-days in 2023. Over the past decade (2015–2024), heatwave exposure increased by 254%, rising from 460 million person-days in 1991–2000 to 1.63 billion person-days. This increase was caused by both a growing number of older adults and infants and a 129% increase in the number of heatwave days. In 2024, older adults in eastern Europe were the most affected, experiencing an average of 34.5 heatwave days per person.
Physical activity-related heat stress risk
Extreme heat can make it harder and less safe to exercise outdoors by increasing the risk of heat-related illness. The Lancet indicator measured the number of hours when temperature and humidity makes outdoor activities such as walking (light activity) or jogging (moderate activity) unsafe due to heat stress. It also accounts for changes in population over time. In 2024, people in Europe experienced a record 182 hours of conditions that posed at least a moderate heat stress risk for light physical activity-113 hours (166%) more than the average between 1991 and 2000. Compared with 1991–2000, the average number of risky hours for moderate physical activity increased by 60 hours (88%) across Europe during 2015–2024.
Figure: Annual hours per person during which light outdoor physical activity (eg, walking) incurred a risk of heat-related illness.
Heat-related mortality
Heat-related deaths are increasing across Europe as temperatures continue to rise. In 2024, an estimated 62,775 people died from heat-related causes. Future projections suggest that heat-related deaths will increase sharply between 2050 and 2100, outweighing the expected decline in deaths caused by cold weather. Between 2015 and 2024, heat-related mortality increased in almost every monitored region in Europe (820 out of 823 regions). On average, this meant 52 more heat-related deaths per million people each year compared with 1991–2000. The largest increases occurred in southern and south-eastern Europe. This report uses an improved method to estimate heat-related deaths more accurately by accounting for the delayed and non-linear effects of high temperatures on mortality.
Figure: Change in heat-related mortality expressed as the increase in annual deaths per million inhabitants in Europe, comparing 1991–2000 with 2015–24.
These findings highlight the critical importance of prioritising both climate change mitigation and effective climate-health adaptation measures to protect populations from the growing health threats posed by rising temperatures.
Read full article here: The Lancet Countdown Europe report 2026
Reference: Kriit H, Chen-Xu J, Semenza J et al.The 2026 Europe report of the Lancet Countdown on health and climate change: narrowing window for decisive health action, The Lancet Public Health, 2026; 11, e386-e407
