How to Stay Safe During a Heat Wave

Here's how to stay cool, reduce your home's temperature, recognize heat stroke symptoms, and avoid heat-related illnesses in general.

outdoor thermometer on red backgroundGetty Images,

The health ramifications of a heat wave are no joke: there are approximately 4,100 trips to the emergency room (ER) in the U.S. for heat stroke in the summer months, according to a 2014 study in the journal Injury Epidemiology.

Heat illnesses include heat cramps, heat exhaustion, and the most severe type, heat stroke. Heat stroke is of particular concern because the core body temperature reaches 104 degrees or higher, which can cause the central nervous system to malfunction.

Heat stroke has several warning signs and symptoms, including headache, dizziness, nausea, confusion, and vomiting. The skin may be hot and dry, and people may even have seizures or lapse into a coma. Heat stroke is a medical emergency that requires calling 911.

Heat exhaustion, on the other hand, isn’t as severe. It causes heavy sweating, a rapid pulse, nausea, and other symptoms, but moving to a cooler location, loosening clothes, and sipping water can help bring the body temperature down.

How dangerous is a heat wave?

While summer’s hot weather can pose a risk at any time, heat waves in particular can be dangerous. They can increase the risk of heat-related illnesses if you don’t have air conditioning—or even if you do.

“Heat waves pose additional risks of severe weather, which can cause power outages that knock out air conditioning,” says Brad Uren, MD, assistant professor in emergency medicine at Michigan Medicine in Ann Arbor.  (Here are tips for staying cool in the summer heat.)

Another problem? Heat waves can be sudden, and your body may not yet be adjusted to the higher temperatures.

“Our body has the ability to acclimate to a number of environmental stresses, including heat, cold, and altitude, but it needs time,” says Sam Torbati, MD, co-chair and medical director of the Ruth and Harry Roman Emergency Department at Cedars-Sinai in Los Angeles. “The faster the change in environmental conditions, the higher the risk of becoming ill,” he adds. (Learn some quirks and facts about body temperature.)

Who’s most at risk in a heat wave?

Men, people who are older, and those who live in the South are at the greatest risk of heat stroke, according to the Injury Epidemiology study.

People who are elderly are less able to tolerate temperature swings, which makes them more vulnerable in hot weather. In fact, older people may not even realize that their house or apartment is getting dangerously hot, which puts them at risk for getting sick.

Certain health conditions can also raise the risk of heat-related illness. “People who are obese, have underlying chronic medical conditions, and individuals on certain medications, are particularly at higher risk for heat-related illness because they lack the mechanisms used by the body to counteract the effect of excessive heat through sweating,” says Dr. Torbati.

Those medications include anti-hypertensives, diuretics, antihistamines, decongestants, and antidepressants, he says. Also, know that alcohol and caffeine can impair your body’s natural ability to cool down. (Beware of the sneaky ways summer makes you sick.)

In addition, babies and toddlers who are under age two need additional protection during a heat wave. “Young babies have a more difficult time regulating their temperature,” says Dr. Uren.

Reduce indoor daytime temperatures

The temperature inside your home is usually higher during the day as the sun comes through your windows and heats up your home, and then tends to drop at night. Dr. Uren advises closing your curtains to keep sunlight out and to lessen this natural rise in temperature.

If your home has a garage, shut your garage door to provide a buffer between outside and inside. The large open space invites heat in that can make your home even hotter.

If you don’t have an air conditioner (or even if you do) putting up awnings on south-facing windows is another strategy for keeping your home cool. (These are the health problems that feel worse during summer.)

Open your windows at night

Whereas you want to keep out the hot air in the day, you want to invite cooler air into your space at night.

“Open up all of your windows when the sun goes down,” says Dr. Uren. (Close them right before sunrise when the outside air is beginning to heat up.)

Limit your use of certain appliances

Take a minute to think about what tasks you are doing that add heat and humidity to your home. Those things may include showering, washing dishes, running the dishwasher, starting the washer and dryer, and cooking.

“Try to time those events appropriately,” says Dr. Uren. For example, if you have a programmable dishwasher, set it to run at 3 a.m. Take a shower at night. (Find out how weather affects skin.)

Use an outdoor grill, prepare no-cook meals, or order in (if it’s in your budget) for dinner, rather than heating up your home by using your oven or other cooking appliances.

If you can set up a clothesline outside, hang clothes up to dry so you don’t add extra heat to your home from your clothes dryer, he says.

young woman sitting in front of fan at homeSandy Aknine/Getty Images

Use ice or spray your skin with water

Assuming you have electricity and a fan, Dr. Torbati recommends this hack: put a bowl of ice in front of a fan. “As the ice melts, the fan’s breeze distributes the vapor, giving you a cool breeze,” he says.

Other options, says Dr. Torbati: soaking your feet in cold or icy water when you need to cool down quickly or spritzing your face and neck with cool water. (Also, check out the most hydrating foods to eat.)

How to prepare for a heat wave

Scientists say sweltering your way through summer will become more common as climate change brings about a greater risk of dangerously high temperatures. Just like you would prep for other emergencies, you should prepare for a heat wave, says Dr. Torbati.

That includes having extra fans on hand in case your air conditioner fails. Make sure you have lightweight cotton clothing around to stay cool. If you have a basement, you can head down there if temperatures get too high. And it’s a good idea to know where your local cooling center is located, he advises.

Cooling centers are places in your community such as a library, school, or community center that are specifically set up to provide air conditioning or other measures to help people stay safe when temperatures climb to dangerously high levels. If you live in a home without an air conditioner or the power has been knocked out, community cooling centers become vital to your well-being.

While visiting a nearby beach or lake could be another way to stay cool, the current Covid-19 pandemic can make that a little riskier, says Dr. Uren. (Stay cool and safe during coronavirus with these summer face masks.)

“It can be a challenge to be able to find appropriate ways to cool off that doesn’t bring you around crowds,” he says. It may be safer right now to go to a family member or close friend’s home and keep the necessary six-foot physical distance. (Find out whether summer heat kills coronavirus.)

Know the warning signs of heat illness

If there’s one thing to remember when it comes to heat-related illness, is to trust your instincts, says Dr. Uren.

“The people who wait too long and get into trouble tell me that they knew something was wrong but kept on going,” he says. If you begin to feel symptoms like feeling woozy, dizziness, or a headache, seek out shade or head to a cool area, like a basement. Make sure to rest, drink some water, and see if you begin to feel better, he adds. (Exercising outdoors? This is how to beat summer workout dangers.)

Never assume that just because you’re still sweating that you’re okay. “Stopping sweating happens very late in heat illness and is not something you’re likely to notice yourself,” says Dr. Uren. Instead, someone you’re with might notice that you’re confused, are having trouble walking, or look intoxicated.

Remember to check in on older adults to make sure they’re okay, adds Dr. Torbati. “Don’t assume they’re just resting. Their lack of interaction may be due to heat illness,” he says.

When to seek help

Some symptoms of heat illness (like muscle cramps or nausea) can be managed on your own by taking the above steps, like seeking a cool place, drinking water, and resting. However, the Centers for Disease Control and Prevention advises getting medical help for heat cramps if they last longer than one hour or if you’re on a low-sodium diet or have heart problems.

Get help for heat exhaustion if you’re throwing up or if symptoms last longer than an hour or get worse. If heat stroke is suspected, call 911 immediately.

Popular Videos

  • Injury Epidemiology: "Emergency Department Visits for Heat Stroke in the United States, 2009 and 2010"
  • Centers for Disease Control and Prevention: "Warning Signs and Symptoms of Heat-Related Illness"
  • Brad Uren, MD, assistant professor in emergency medicine at Michigan Medicine in Ann Arbor
  • Sam Torbati, MD, co-chair and medical director of the Ruth and Harry Roman Emergency Department at Cedars-Sinai in Los Angeles