Why extreme heat is much more dangerous for the elderly than we realised

What the report says

Stanford University researchers, in a study published by Al Jazeera on 19 Aug. 2026, say the danger extreme heat poses to older adults has likely been underestimated. The research argues that age sharply lowers the body’s ability to tolerate heat, meaning people 65 and older can reach unsafe conditions at lower temperatures than younger adults. The findings come as climate change is increasing the frequency and severity of heatwaves worldwide.

The report says earlier assessments often treated heat tolerance as if it were the same for everyone, which masked the risk for ageing populations. As people get older, the body sweats less and the heart must work harder to cool itself. The study links heat exposure to serious outcomes including heatstroke and worsening of existing heart, kidney and lung conditions, which can contribute to illness and death during hot weather.

Al Jazeera reported that the global population is ageing quickly, and that older people in low-income countries such as China, India and Pakistan may face the highest risks as warming continues. The researchers estimate that the amount of annual exposure to heat beyond age-specific tolerance levels is already more than twice what previous work suggested, and that each additional degree of global warming could bring about roughly one billion more people into that danger zone.

The study also outlines possible responses, including more green space, better ventilation, cooling centres, stronger heat warnings and wider access to indoor cooling. It says cutting emissions remains essential, but stresses that planning for heat now is especially important for medically vulnerable and socially isolated older adults.