Nature, 8 July 2025

Strategies for heat-health preparedness should concentrate on cooling people, not just the air

To save lives in heatwaves, focus on how human bodies work

Close to 110,000 heat-related deaths are estimated to have occurred in Europe during the summers of 2022 and 2023 combined. That’s roughly the same number of people as if a fully occupied jumbo jet crashed every day for 16 weeks. Meanwhile, a vast array of heat-related impacts disrupt people’s lives. Hot weather worsens mental-health problems, increases the likelihood of violence and makes pregnant women more likely to give birth prematurely. In classrooms, it impairs children’s ability to learn.

The problems are expected to get much worse. Without better adaptation, heat-related deaths are projected to rise 3.7-fold by mid-century if global temperatures reach 2 °C above pre-industrial levels. (In 2024, the average global temperature exceeded 1.5 °C above pre-industrial levels for the first time.) And heat stress in the workplace is expected to cost the global economy US$2.4 trillion each year in lost productivity by 2030.