The world is getting hotter, and it’s not doing any favors for our health, physically or biologically. The effects of extreme heat, such as heat stroke, and an increased risk for cardiovascular disease, have already become common knowledge. Yet little is known about the biological effects of escalating high temperatures.
Is The Heat Aging You?
Climate change is a real-life issue, so it’s important to understand how this may affect our longevity. With that, this article examines a recent study whereby researchers set out to investigate how long-term exposure to extreme heat may speed up biological aging, which has been linked to an increased risk for early mortality, heart disease, and stroke.
Taking data from the Health and Retirement Study, featuring 3,686 adults aged 56 and older across the United States, the researchers analyzed blood samples collected in 2016-2017. They measured DNA methylation patterns to identify whether the individuals were aging biologically faster or slower than their chronological age.
The team of scientists then worked to calculate heat days according to the National Weather Service heat index:
- “caution” level (80°F-90°F)
- “extreme caution” (90°F-103°F)
- “danger” (103°F-124°F)
They then examined the link between more heat days and accelerated biological aging – whilst accounting for factors like age, sex, race/ethnicity, physical activity, drinking and air pollution.
High Heat, Faster Aging
“Participants living in areas where heat days, as defined as Extreme Caution or higher levels (≥90°F), occur half the year, such as Phoenix, Arizona, experienced up to 14 months of additional biological aging compared to those living in areas with fewer than 10 heat days per year,” – Eun Young Choi, study lead author
The findings, published in Science Advances, found that older adults living in areas prone to temperatures of 90 degrees or above displayed more accelerated aging at a molecular level compared with those in areas with lower temperatures. These results remained true even after the researchers controlled for several factors, with the team determining that, “Just because you live in an area with more heat days, you’re aging faster biologically.”
While short-term heat exposure allowed for the bodies to recover, long-term heat exposure was more concerning. Individuals in locations with at least 140 extreme heat days per year experienced up to 14 months of additional biological aging compared to those living in areas with fewer than 10 such days annually.
Bringing Down The Heat
Despite these findings, the research team couldn’t rule out all possible alternative explanations, such as some individuals possibly facing a higher risk due to preexisting health conditions. What’s more, the researchers failed to account for access to air conditioning, which may help to reduce heat exposure.
Nonetheless, with peer-reviewed findings revealing that the frequency, intensity, and duration of extreme heat events are expected to increase dramatically in the coming years, it’s important to work to develop heat mitigation strategies,
“If everywhere is getting warmer and the population is aging, and these people are vulnerable, then we need to get really a lot smarter about these mitigation strategies.” – Jennifer Ailshire, senior author of the study.
Ailshire goes onto emphasis the different ways in which these strategies can be implemented. She suggests placing sidewalks and building bus stops with shade in mind, planting more trees, and increasing urban green space.
Want to know more?
Heatwaves aren’t only speeding up biological aging, as they may also be impacting your mental health. In fact, research has found that raising and boiling temperatures can affect your mental health in the following ways.
References
Abugroun, A., Shah, S. J., Fitzmaurice, G., Hubbard, C., Newman, J. C., Covinsky, K., & Fang, M. C. (2025). The Association Between Accelerated Biological Aging and Cardiovascular Outcomes in Older Adults with Hypertension. The American Journal of Medicine, 138(3), 487-494.e7. https://doi.org/10.1016/j.amjmed.2024.10.029
Choi EY, Ailshire JA. Ambient outdoor heat and accelerated epigenetic aging among older adults in the US. Sci Adv. 2025;11(9):eadr0616. doi: 10.1126/sciadv.adr0616
