The dangers of extreme heat

July 26, 2022 – Extreme heat—the kind that baked the U.S. and other parts of the world in mid-July—poses grave health risks, according to Aaron Bernstein of Harvard T.H. Chan School of Public Health.

Temperatures that soar to 90 degrees Fahrenheit or higher over the course or two or more days can cause more than just dehydration, heat exhaustion, or heat stroke, said Bernstein, interim director of the Center for Climate, Health, and the Global Environment at Harvard T.H. Chan School of Public Health (Harvard Chan C-CHANGE), and other experts quoted in a July 19, 2022 article in STAT. It can lead to flare-ups in chronic conditions such as migraine, arthritis, asthma, kidney disease, hypertension, type 2 diabetes, and cardiovascular disease, according to the article. It can also worsen mental health and can increase the chances of being injured at work, having a heart attack, or getting an infection.

“We’re warm blooded,” Bernstein told STAT. “Our whole body is designed to operate within a narrow range of temperatures.”

Extreme heat is often hardest on people with low incomes and communities of color, who the article noted are more likely to live in so-called heat islands—areas that are hotter than surrounding areas because they contain a lot of roads and buildings that absorb and retain heat, and lack heat-abating tree cover and green space. These groups may also lack access to air conditioning.

Bernstein also spoke about the dangers of heat in a July 21, 2022 NPR article. “When our body gets too hot, things don’t work normally,” he said. Too much heat “makes our hearts and our lungs and our brains and even our kidneys and other organs not work well. And so what we see as a consequence of those things is certainly people who have existing heart problems, lung problems, kidney problems, even mental health issues—they get sicker. And even for people who are in generally good health, the heat can be really dangerous if we don’t pay attention.”

In a July 20 NBC News article, Bernstein spoke about the importance of a coordinated federal response to climate change to address the problem of extreme heat as well as other climate-related shocks such as dangerous storms and worsening air pollution. “We have no such response from our federal government right now,” he said.

Read the STAT article: It’s not just heat stroke. Extreme temperatures pose special risk to people with chronic illness (and that’s a lot of us)

Listen to or read the NPR article: What extreme heat means for our long term health

Read the NBC News article: As heat waves kill thousands, Biden’s office of climate health risks is broke

Learn more

Health-harming extreme heat, driven by climate change, on the rise (Harvard Chan School news)