Sign in the desert that says Caution! Extreme Heat Danger.

Extreme heat may speed up aging at the molecular level

Older adults living in hotter areas experience biological aging at a faster rate, according to a new study linking extreme heat to molecular changes in DNA.

Mohana Ravindranath reports for The New York Times.


In short:

  • Researchers analyzed blood samples from over 3,600 older adults and found those exposed to frequent extreme heat showed accelerated epigenetic aging.
  • The study linked living in areas with 140 or more days above 90°F per year to aging up to 14 months faster than those in cooler areas.
  • Scientists caution that while heat exposure and aging appear connected, more research is needed to determine causation and other contributing factors.

Key quote:

“DNA is like a blueprint,” but these epigenetic changes are like the “switchboard that controls which part of the blueprint gets activated.”

— Eun Young Choi, postdoctoral associate at the U.S.C. Leonard Davis School of Gerontology

Why this matters:

The effects of extreme heat on human health are well documented, with studies linking high temperatures to heat stroke, cardiovascular strain, and even mental health challenges. But emerging research suggests that heat may also take a toll at the cellular level, potentially accelerating aging itself. If heat exposure alters the biological mechanisms of aging, it could mean a greater burden of chronic illness and declining health in later years.

While this study opens the door to new questions, scientists caution that much remains unknown. Are these cellular changes reversible? How much heat exposure is too much? And are certain populations more at risk? As global temperatures rise, these are critical areas for future research.

Related: Increasing temperatures from climate change may harm babies' hearts

3 women in different colored head scarves sitting on ground with a child.

Opinion: Global warming is a crisis of inequality

Climate change-driven disasters often strike hardest where inequality, colonial legacies, and poor infrastructure leave communities most exposed and least protected.

Friederike Otto writes for The Guardian.

Keep reading...Show less
Sunrise in the woods

Get our Good News newsletter

Get the best positive, solutions-oriented stories we've seen on the intersection of our health and environment, FREE every Tuesday in your inbox. Subscribe here today. Keep the change tomorrow.

red road bike beside red and white wooden maple leaf painted wall.

Climate change fades in Canadian election as voters prioritize economy and U.S. tensions

Climate change, once a leading issue for Canadian voters, has slipped down the list of priorities in the 2025 federal election amid growing concerns over the economy and U.S. political instability.

Julia-Simone Rutgers reports for The Narwhal.

Keep reading...Show less
Scientist wearing safety glasses working in a lab.
Credit: CDC/Unsplash

Governor of Massachusetts warns against brain drain due to GOP science funding cuts

Massachusetts Gov. Maura Healey warned that President Trump’s attacks on research institutions and funding cuts are driving scientists out of the U.S. and weakening the country’s global leadership in science.

David Cohen reports for POLITICO.

Keep reading...Show less
The extension .org in woodblocks next to a cup of coffee.

Trump signals crackdown on environmental nonprofits by targeting their tax-exempt status

Environmental organizations across the country are bracing for executive orders from President Trump that may challenge their tax-exempt status and chill legal and advocacy work.

Marianne Lavelle and Lee Hedgepeth report for Inside Climate News.

Keep reading...Show less
An oil rig in the middle of the ocean at sunset, with purple clouds and sea and an orange sky.

Fifteen years after the Gulf oil spill, health claims stall as offshore drilling expands

A decade and a half after the Deepwater Horizon disaster, many Gulf Coast residents and cleanup workers still struggle to receive compensation for alleged oil-related health problems, even as environmental restoration slows and offshore drilling ramps up.

Jack Brook reports for The Associated Press.

Keep reading...Show less
A porch with a flag on the front of it.

Climate-fueled disasters and inflation drive Texas homeowners to face soaring insurance costs

A growing number of Texas residents are struggling to afford or even obtain home insurance as intensifying weather and economic pressures drive premiums to record highs.

Anna Phillips reports for The Washington Post.

Keep reading...Show less
Two men wearing sun hats standing in a field of plants.

Agroforestry cuts deforestation in Southeast Asia, but success depends on local policies

Agroforestry systems have reduced deforestation across Southeast Asia over the past eight years, but new research finds that without the right policies, they can also drive forest loss.

Carolyn Cowan reports for Mongabay.

Keep reading...Show less
From our Newsroom
Regulators are underestimating health impacts from air pollution: Study

Regulators are underestimating health impacts from air pollution: Study

"The reality is, we are not exposed to one chemical at a time.”

Pennsylvania governor Josh Shapiro speaks with the state flag and American flag behind him.

Two years into his term, has Gov. Shapiro kept his promises to regulate Pennsylvania’s fracking industry?

A new report assesses the administration’s progress and makes new recommendations

silhouette of people holding hands by a lake at sunset

An open letter from EPA staff to the American public

“We cannot stand by and allow this to happen. We need to hold this administration accountable.”

wildfire retardants being sprayed by plane

New evidence links heavy metal pollution with wildfire retardants

“The chemical black box” that blankets wildfire-impacted areas is increasingly under scrutiny.

People  sitting in an outdoors table working on a big sign.

Op-ed: Why funding for the environmental justice movement must be anti-racist

We must prioritize minority-serving institutions, BIPOC-led organizations and researchers to lead environmental justice efforts.

joe biden

Biden finalizes long-awaited hydrogen tax credits ahead of Trump presidency

Responses to the new rules have been mixed, and environmental advocates worry that Trump could undermine them.

Stay informed: sign up for The Daily Climate newsletter
Top news on climate impacts, solutions, politics, drivers. Delivered to your inbox week days.