What ER Doctors Want You to Know About Extreme Heat

A woman cools off from the heat with a bag of ice cubes on a summer day in Manhattan, on July 29, 2002. (Richard Perry/The New York Times)
A woman cools off from the heat with a bag of ice cubes on a summer day in Manhattan, on July 29, 2002. (Richard Perry/The New York Times)

The heat index hit 112 degrees in Miami this week. Monkeys have been dropping dead amid scorching heat in Mexico. India is experiencing its latest heat crisis.

With warmer temperatures comes a greater potential for heat-related illnesses. Rates of emergency room visits for conditions related to heat rose substantially in many parts of the United States last summer, according to the Centers for Disease Control and Prevention. And weather experts are again predicting above-normal temperatures in much of the country this summer.

We asked emergency room doctors around the country what the public should know about extreme heat.

Sign up for The Morning newsletter from the New York Times

Heat-related illnesses range from minor to life-threatening.

Mild heat illnesses include heat rash; swelling in the hands and feet; muscle cramps; and heat syncope, or a fainting episode after standing too long or getting up suddenly. People with heat exhaustion have more severe symptoms, which could include headache, nausea, vomiting and dizziness.

Dr. Hany Atallah, an emergency medicine physician and the chief medical officer of Jackson Memorial Hospital in Miami, said heat exhaustion is the most common heat-related illness he sees in the ER. Doctors can usually help patients cool down and hydrate properly and, within a few hours, discharge them, he said.

Heat stroke, which can be caused by exposure to extreme heat or strenuous exertion in high temperatures, is less common but much more dangerous. The hallmark signs are a core body temperature above 104 degrees; and confusion, seizures or other mental status changes in the context of extreme heat exposure.

“The body’s ability to cool itself is impaired,” Atallah said. The condition can lead to brain damage, muscle breakdown and kidney failure.

“When those patients come into the emergency department, it’s all hands on deck to get all the patient’s clothes off, cool them down as quickly as possible, give them IV fluids and any other kind of support,” Atallah said.

In extreme cases, patients experiencing heat stroke may require the support of a machine that takes over heart and lung functioning, said Dr. Jacquelyn Bowers, director of emergency services at Ochsner LSU Health System of North Louisiana.

Cooling and fluids are essential.

If you’re showing any signs of heat-related illness, the best thing you can do is get into a cool environment and hydrate — quickly. This may be as simple as hopping into a car, cranking up the air conditioner and drinking some cool fluid. “Those things are all going to help,” Atallah said.

Take off layers or any restrictive clothing. If you’re out on a hike or at the beach, find some shade or get in the water.

“Going deep in cold water is going to make you colder faster,” said Dr. Jose Burgos, a hospitalist at University Medical Center of El Paso.

If you are indoors, take a cold shower or cold bath and turn on a fan. Air blowing on wet skin will help sweat to evaporate and your body to cool down, said Dr. Ronna Campbell, an emergency medicine physician at the Mayo Clinic in Rochester, Minnesota.

If you’re really dehydrated and feeling sick, Bowers said, sports drinks or water with salt tablets will help restore electrolytes like sodium that you lose by sweating and that are needed to maintain fluid balance.

Minutes matter.

If you have tried cooling down and drinking fluids, but the symptoms haven’t improved in a half-hour or are getting worse, go to the emergency room, Bowers said.

Experts also said to seek immediate care if you or someone you know is having heat-related symptoms and is not able to get out of the heat, seems disoriented or is having seizures.

If heat stroke isn’t recognized and treated quickly, “it can cause deterioration rapidly, within minutes,” Bowers said. “We really have to address this as the emergency it is.”

Children and older people are more susceptible.

Children are particularly at risk in extreme heat, doctors said. They tend to heat up faster, but they lack mechanisms to compensate because their systems are immature. They sweat less, for example, Campbell said. And they may not hydrate enough. “They’re having fun and they forget that they need to drink,” she said.

Older people are also at high risk. They are more likely to have chronic medical conditions such as diabetes, kidney disease and heart failure that interfere with the body’s ability to regulate temperature and balance fluids, Burgos said. And treatments for some of these conditions, like blood pressure medications that keep the heart rate down or diuretics that clear fluid out of the body, can impair the body’s ability to compensate for extreme heat. People with depression or dementia may also not realize they’re thirsty and forget to drink water, Burgos said.

Patients with these conditions should talk to their primary care doctor, cardiologist or nephrologist about how to adjust to extreme heat, Burgos said. “We have to educate them about how to deal with their fluid restrictions and medications and to watch for symptoms,” he said.

Adjust your routine during extreme heat.

When temperatures surge, smart choices can make a big difference, doctors said. Avoid physical activity outdoors during the hottest part of the day, if you can. (Check your local weather forecast to make a plan.) Go to a cooling station or mall, even if only for a couple hours, if you lack air conditioning at home.

When you do go out or exercise in the heat, wear loosefitting, light-colored clothing, which will absorb less heat and help keep your body cool. Stay hydrated, even when you don’t feel thirsty. Avoid alcohol, which can dehydrate you and may impair your ability to recognize if something is wrong.

Pay attention to the weather. In very humid places such as South Florida or Louisiana, heat is more dangerous even at lower temperatures. Sweat will evaporate less quickly off the skin, “so it’s harder for the body to cool itself,” Campbell said.

By contrast, in the desert where Burgos practices, dry conditions, a lack of natural shade and strong, direct sun exposure will make you feel “like you’re in an oven,” he said. People can easily overheat.

If you know you’re going to be in extreme heat and doing strenuous work or exercise, it’s important to have a plan to acclimatize your body safely over time. Research suggests that you can get your body used to the temperature by gradually increasing your activity in a hot environment over one to two weeks, and taking breaks to cool off and hydrate properly.

c.2024 The New York Times Company