Heatstroke mortality in a warming world

Global temperatures averaged more than 1·5°C above pre-industrial levels between 2023 and 2025, bringing the world close to the long-term temperature limit set by the Paris Agreement on climate change.1 Recent heatwave events of record-breaking magnitude, such as the 2024 Sahel heatwave where temperatures exceeded 45°C with devastating population health impacts, have been deemed impossible without climate change.2 Greenhouse gas emissions continue to rise year on year.1 Understanding the health impacts of heat is therefore increasingly urgent, with existing evidence highlighting a range of effects from mortality to morbidity.