Nature, 26 August 2025

Repeated heatwaves can age you as much as smoking or drinking

Long-term exposure to extreme heat events accelerates the body’s ageing process and increases vulnerabilities to heath issues, finds a long-term study of 24,922 people in Taiwan.

The study, published today in Nature Climate Change, suggests that moderate increases in cumulative heatwave exposure increase a person’s biological age — to an extent comparable to regular smoking or alcohol consumption. The more extreme-heat events that people were exposed to, the more their organs aged. This is the latest study to show that extreme heat can have invisible effects on the human body and accelerate the biological clock.