The exhaustion and dehydration resulting from extended exposure to high temperatures are sensations familiar to everyone. However, research now suggests that the impact of being subjected to extreme heat extends beyond immediate heatwaves: consistent exposure to elevated temperatures could also lead to accelerated aging.
A recent study, published on August 26 in the journal Nature Climate Change, found that repeated exposure to heat waves was associated with faster biological aging and increased susceptibility to health issues. The more instances of extreme heat an individual encountered, the more their bodies aged.
Researchers analyzed medical data from nearly 25,000 people in Taiwan over a 15-year period, specifically between 2008 and 2022, during which the region experienced 30 heat waves (defined by the study authors as a “period of elevated temperature over several days”). They determined a person’s biological age using results from various medical tests, including assessments of liver, lung, and kidney function, blood pressure, and inflammation. Participants’ addresses from the two years prior to their medical visit were then used to compare their biological ages with the temperatures they were likely exposed to.
Their findings indicated that the more extreme heat events a person endured, the more quickly they aged, with each additional 1.3°C of total cumulative heat contributing approximately eight to twelve days to their biological age. Manual laborers and those residing in rural areas experienced the most significant health impacts.
“While the number itself may look small, over time and across populations, this effect can have meaningful public-health implications,” Cui Guo, the lead study author and an environmental epidemiologist at the University of Hong Kong, told .
Climate change is causing extreme heat events to become more prevalent globally. The year 2024 was recorded as the warmest year on record, surpassing the previous record set in 2023. A separate study revealed that 88% of 247 major U.S. cities have experienced an increase in the number of extremely hot days since 1970.
Climate models forecast that global temperatures will continue to rise, with the World Meteorological Organization predicting a 70% chance that the five-year average warming for 2025 to 2029 will exceed 1.5 °C. As temperatures increase, experts emphasize that developing solutions to mitigate extreme heat will become progressively more critical.