More than 150,000 people worldwide are estimated to die from heatstroke each year, and a new study shows regional differences in heat-related deaths. More than 150,000 deaths each year worldwide between 1990 and 2019 were linked to heatwaves. This is evidenced by a new study published today (May 14). PLoS Medicine Yuming Guo and colleagues from Monash University in Australia.

Heat waves, periods of extremely high ambient temperatures lasting several days, can cause tremendous thermal stress on the human body. Studies have previously measured the impact of individual heatwaves on excess mortality in local areas but have not compared these statistics globally over such a long period of time.

Research methodology and data analysis

In the new study, researchers used data from the Multi-Country City Collaborative (MCC) Network, which includes daily deaths and temperatures in 750 locations in 43 countries. Using MCC data, researchers estimated heat wave deaths worldwide between 1990 and 2019 and mapped the variation of these deaths across continents.

Deaths due to extreme heatwaves during the hot season from 1990 to 2019 amounted to 153,078 deaths per year, or a total of 236 deaths per ten million people, or 1% of global deaths. The highest estimated number of deaths occurred in Asia, while the highest population-adjusted rate was in Europe, with 655 deaths per ten million people. A significant estimated burden of death was also observed in southern and eastern Europe, as well as in the region between North Africa, the Arabian Peninsula and South Asia.

Regional differences in heatwave death rates

At the national level, Greece, Malta and Italy had the highest excess mortality rates. In general, the highest heatwave death rates were observed in regions with dry climates and low average income. Understanding regional disparities in heatwave mortality is key to local adaptation planning and climate change risk management.

“Heat waves are associated with a significant burden of death that has varied spatio-temporally across the world over the last 30 years,” the authors say. “These findings point to the potential benefits of government action to improve the cohesion and resilience of the health sector by addressing inequalities across societies.”

Overcoming the unbalanced impact of heat waves

The authors add: “In the context of climate change, it is extremely important to address the issue of unequal impacts of heatwaves on human health. This requires a comprehensive approach that not only tackles the immediate health risks of heatwaves, but also implements long-term strategies to minimize vulnerability and inequality.” Strategies include: climate change mitigation policies, heat action plans (e.g. heat early warning system), urban planning and green infrastructure, social support program, health and medical services, education and participation and participation community”.