As heatwaves continue around the world due to the climate crisis, research results have emerged indicating that prolonged exposure to high temperatures accelerates human aging. The heatwave has long-term effects on health and the aging process beyond merely feeling hot, and researchers warned it can cause damage comparable to that of smoking, drinking, or lack of exercise.
Researchers at the University of Hong Kong noted on the 25th (local time) that they confirmed through their findings that "heatwaves accelerate biological aging and can have long-term harmful effects on health," as published in the journal Nature Climate Change.
Previous studies have reported that outdoor heatwaves promote aging in older adults. This study is the first to assess the long-term effects of heatwaves.
The researchers tracked 25,000 adults in Taiwan over 15 years, comparing the number of days of heatwave exposure with biological age (a measure of overall health status). They calculated each person's biological age based on blood pressure, inflammation levels, and organ function.
As a result, individuals exposed to heatwaves for 4 more days over 2 years had a biological age that was approximately 9 days older. This effect was similar in magnitude to existing health risk factors such as smoking, drinking, diet, and lack of exercise.
In particular, laborers showed about 3 times faster aging despite the same exposure to heatwaves, and residents in rural areas and communities lacking air conditioning were significantly more affected by the heatwaves.
Professor Cui Guo, who led the study, said, "If exposure to heatwaves accumulates over decades, the health impacts will be much greater than what we have reported," adding that "heatwaves are occurring more frequently and lasting longer, so the health impacts may increase further in the future."
Continuous heatwaves were analyzed as weakening cellular resilience, leading to cumulative damage. While the researchers have not fully elucidated the precise process by which heatwaves accelerate aging, they hypothesized that prolonged exposure to high temperatures may alter cellular DNA or shorten "telomeres," which protect chromosome ends, causing cells to age faster.
Scientists emphasized that while the increase in biological age may seem modest, this is just a result over 2 years. The researchers plan to investigate the impact of heatwaves on lifetime aging in the future.
Paul Beggs, a professor at Macquarie University in Australia who did not participate in the study, said, "This study proves that exposure to heatwaves affects the rate of aging," and added, "Combined with existing research that shows early exposure to high temperatures negatively impacts brain cognitive development, the scope and severity of the health effects of heatwaves can be considered even greater."
References
Nature Climate Change (2025), DOI: www.doi.org/10.1038/s41558-025-02407-w