Why ignoring high temperatures is a big health mistake

SALT LAKE CITY — Summer is sizzling and experts have been warning about heat domes and other temperature-related dangers. But what does that mean and why so much concern?

It's a simple but largely unrecognized fact that heat kills more people than any other weather feature — no competitor comes close. And while those most at risk are children, older adults, pregnant women and sick or overweight individuals, according to Ready.gov, anyone can fall victim to high temperatures.

Having heat sickness once also creates lifelong vulnerability.

To understand the lethal power of extreme heat, one need only consider the annual Hajj pilgrimage to Mecca in Saudi Arabia in June, where an estimated 1,300 people died in record-breaking temperatures.

In the Intermountain West, the Phoenix area has six confirmed heat deaths already this summer and is investigating nearly 90. Two people died of heat-related causes in Idaho, typically considerably cooler than many U.S. states.

Unusually hot temperatures are also cause for concern for athletes, for members of The Church of Jesus Christ of Latter-day Saints reenacting pioneers entering the Salt Lake Valley, for construction workers and road crews, for employees in poorly ventilated manufacturing plants, for gardeners, for unhoused people, for illicit drug users and people taking certain prescriptions, for agricultural workers, for jailed individuals, for military personnel, for firefighters and police and for low-income individuals without air conditioning, among others. And, of course, for those who care about any of them.

Heat should, in fact, concern us all.

An Associated Press analysis of data from the Centers for Disease Control and Prevention found that a record number of U.S. deaths in 2023 — more than 2,300 — mentioned heat on the death certificate. Sweltering temperatures contributed to 1,670 U.S. deaths in 2022, per CDC. And 2024 is apt to bring high numbers, too, unless people start taking precautions.

Who are the most vulnerable

"Heat stroke can be really dangerous; it has a pretty high mortality rate, actually," said Dr. Keli Kwok, assistant medical director at Intermountain Health's Intermountain Medical Center emergency department. "Anytime your temperature increases, your metabolic needs increase, too. That means your heart rate needs to go up to keep up with the metabolic needs of your body and your respiratory rate needs to go up to keep up with the oxygen need. Anybody who is not ideally conditioned is going to have a harder time."

Young children and adults 65 and older are at risk of heat illness simply by virtue of age, she said.

Anyone is susceptible if conditions are right. Being severely overweight or in poor physical condition raises the risk that heat will cause harm. Diabetes, heart disease and kidney problems are worsened when it's too hot. Not being used to working in high temperatures and heavy work both pose danger. Dark or heavy clothing amplifies heat. People in uniforms or industrial protective equipment are at elevated risk.

Alcohol use worsens heat's effect, Kwok said. Someone older or diabetic who imbibes will have increasingly lower ability to handle heat.

During pregnancy, the combination of heat and air pollution raises the risk of premature birth and low birthweight, said Dr. Lisa Patel, a pediatrician in the San Francisco Bay area who is executive director of the Medical Society Consortium on Climate and Health. It may contribute to stillbirth.

Related:

As temperatures approach 100, urban surfaces can make the heat even more present

When temperatures approach and reach triple digits, heat captured and reflected by surfaces can make conditions in urban areas only more sweltering.

Infants are especially vulnerable their first week of life because they don't have good thermoregulation, she said. Add in other factors, like whether the family has access to air conditioning, and risk rises.

Patel also points to the danger of leaving children in cars on hot days. "So far in 2024, two deaths have been reported. On average, 37 children under 15 die each year from heatstroke after being left in a vehicle," reports the National Safety Council. Cars can act like an oven even on overcast days.

Scientific American reported that 9,000 high school athletes a year are treated for heat-related illness. Patel said she has cared for teenagers whose coaches worked athletes harder than they should, not recognizing that temperature needn't increase much to become perilous.

Athletic kids may put themselves in danger because they're anxious to impress their coach. That can be true of workers, as well, said Dr. Ronda McCarthy, national director of Medical Surveillance Services for Concentra.

The effect of extreme heat on the body

Unseen damage can occur, too. Severe dehydration damages kidneys and while it's often reversible in the young, "every time the kidney takes a hit, we know it can result in chronic kidney disease and damage down the line," she said.

For older adults, danger can be simple physiology. When the body heats internally, the heart pumps hard to get blood to the skin, which causes sweating. That cools blood through evaporation so the cooler blood can cool the rest of the body. The process may falter in older people, causing the heart to strain to keep up. Sometimes, it can't.

Said Patel, "In a long heat wave, the heart never gets a break."

Read the entire story at Deseret.com.

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