Extreme heat accelerates ageing in older adults

Ageing is natural. But the rate of ageing varies from human to human. As we go through life, our bodies are affected by stresses and shocks. Sustained heat stresses our bodies and make them less efficient at doing the many jobs needed to stay alive. This is why it is said to accelerate biological ageing.

While your DNA stays the same, your cells canswitch some of its thousands of genes off or on in responsetostresses.Atanyonetime,onlyafraction of the genes in any cell are turned onmeaning they are busy making proteins. This is known as epigenetics. Cellular changes in DNA can lead to proteins being produced more or less, which in turn canflowontoaffectphysiologicalfunctionsandour health status. This can be both bad or good. Heat stress can alter the pattern of which genes are turned off or on, which in turn can affect our rate of ageing. Severe heat stress can be remembered in cells, leading them to change their DNA patterns over time.

The study found that heat affects older people more than younger people. Our ability to control our body temperature drops as we age, and we are less resilient to outside stresses and shocks. Longer term exposure to intense heat increased biological age by

2.48 years over the six-year period of the study.

Source:ScienceAdvances,2025