It’s not your imagination: It really is hotter than when you were a kid. The nine years from 2013 to 2021 rank among the 10 warmest on record, according to the National Oceanic and Atmospheric Administration. Climate experts warn that bouts of extreme heat are only going to become more common as global temperatures continue to rise.
That’s bad news for older adults, who are more likely to get sick from heat — even die from it.
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Soaring temps send more than 67,500 people in the U.S. to the emergency room each year, according to the Centers for Disease Control and Prevention (CDC). On average, the CDC says heat kills more than 700 Americans annually, though other research suggests the number is actually much higher. A 2020 study published in the journal Environmental Epidemiology, for example, finds an average of 5,608 deaths are attributable to heat each year. Another study from a team of Duke University researchers estimates that 12,000 Americans die annually from heat-related causes.
Regardless of the total tally, most people who die from the heat are over the age of 50, the National Institute on Aging says.
“It has everything to do with our body’s ability to deal with heat as we age,” says Aaron Bernstein, M.D., interim director of the Center for Climate, Health and the Global Environment at the Harvard T.H. Chan School of Public Health. “People who are older, our bodies may not be able to dissipate heat as well as people who are younger. We also tend to have more chronic health problems and may take more medications that affect our body’s ability to deal with heat.”
Here’s a closer look at why heat is such a health risk for older adults, and what you can do to stay safe as heat waves become more frequent.
Cooling down the body becomes harder
People get into trouble when they can’t cool themselves down. That’s when heat exhaustion can occur, often marked by dizziness, fatigue and a weak, rapid pulse. And if that goes untreated, heatstroke can set in, bringing with it the potential for long-term organ damage or death.
Sweating is the top way that humans cool themselves, Bernstein says. It’s not the sweat itself that is particularly cooling, but rather the evaporation process. It takes energy to evaporate sweat off the skin, and the energy source in this equation is heat. So as sweat switches from liquid to vapor, heat leaves your body and you start to cool down.
But sweat glands become less effective with age. “They can’t pump out as much sweat as quickly,” says Daniel Van Durme, M.D., chief medical officer of the Florida State University College of Medicine.
What’s more, several medications common among older adults can interfere with how efficiently the body sweats or handles heat, Van Durme adds, including some antihistamines (to ease allergy symptoms) and drugs used to treat overactive bladder. Certain antidepressants and some blood pressure medicines can also hinder the body’s ability to cool itself — and experts say there are likely many more that inflict this effect.
Another disadvantage for older adults is heat’s impact on the heart. Hand in hand with sweating, the body releases heat by increasing blood flow to the skin to push the heat away from the core. This requires the heart to work harder. “And if you have heart disease, that puts strain on an already potentially weak heart,” Bernstein says. “So you see people during heat events having heart attacks, arrhythmias, strokes — there’s a big risk for that.”