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Here’s How to Stay Cool and Safe When a Heat Wave Hits

Heat-related illness can be deadly—and anyone can be affected.
February 1975 Jill Vinal enjoying a cool greenflower decorated drink while sunbathing in Acapulco.
Slim Aarons via Getty Images

We’re in the thick, sweltering stickiness of summer and extreme heat has blanketed many parts of the country. You’ve likely felt unbearably sweaty, tired, or cranky (or a lovely combination of the three) at some point in the last month—and summer isn’t even over yet.

The National Weather Service (NWS) recently issued a Twitter alert that warned of “dangerous heat” permeating through the Southern Plains and into the mid-South with the hopeful caveat that “some relative relief is on the way.” In early July a heat wave hit northeastern states, breaking record-high temperatures in New York City, Boston, and Philadelphia. Even the Pacific Northwest, which usually hosts mild weather this time of year, is operating under an excessive heat warning from the NWS.

Temperatures have also hit record-breaking numbers in Europe, where the thermostat hit up to 104 degrees Fahrenheit in the U.K.; meanwhile, heat wave–related wildfires broke out in France, The New York Times reported.

A heat wave is defined as a period of unusually hot weather, meaning the temperature needs to be above the historical averages in a certain area for two or more days, according to the National Oceanic and Atmospheric Administration (NOAA). The organization recently tweeted a warning about extreme heat’s “cumulative impact on the body over time,” including very real health risks like dehydration and heat stroke.

Even if temps are starting to cool off in your area, summer’s brutal weather is starting to last longer. Here’s what you can do to stay safe when temperatures in your area start to reach potentially dangerous highs.

How can extreme heat affect the body?

Your biggest concern should be heat-related illness, which includes heat exhaustion, heat stroke, heat cramps, sunburn, and heat rash, according to the Centers for Disease Control and Prevention (CDC). These are the main symptoms to watch for:

  • A body temperature of 103 degrees Fahrenheit or higher
  • Hot, red, or  dry skin
  • Cold, pale, and clammy/damp skin
  • Blisters on the skin
  • A fast, strong pulse
  • Dizziness, confusion, or fainting
  • Nausea or vomiting
  • Muscle cramps, pain, weakness, or spasms
  • Heavy sweating
  • Absence of sweating paired with high body temperature

Older adults, young children, pregnant people, and people with chronic health conditions (both physical and mental) face the highest risk of heat-related illness, but anyone is susceptible to the dangers of extreme heat or consistent heat, J. Luke Pryor, PhD, CSCS, the associate director of elite athlete performance who researches heat stress and hydration at the Center for Research and Education in Special Environments at the University at Buffalo, tells SELF. “A healthy, average person who is physically active, at minimum, should be changing behavior around physical activity and work outdoors, and should try to avoid being outside during times of day that are the hottest,” he says. “Anyone can succumb to potentially deadly heat-related illness.”

First, let’s talk about the growing importance of air conditioning.

Europe’s general lack of air conditioning, particularly in homes, has shed a renewed light on the general reliance on these energy-draining machines in America, The Washington Post reports. That’s because people in European countries historically have not dealt with consistent, scorching temps like those in southern U.S. states. As the Earth’s climate continues to get warmer, experts say unprecedented heat waves are likely here to stay.

And it’s really hard to get reasonably cool without A.C., especially when the weather becomes this stifling. Air conditioning, in addition to cooling your environment, helps take moisture out of the air, Dr. Pryor says. As a result, it supports your body in crucial temperature regulation. “We’re one of the few species on Earth that will give up body water via sweating,” he explains. “When we sweat in a dry environment, it’s more likely to evaporate and take the heat with it. But when we sweat in a humid environment, it’s harder to cool off.”

Because humidity is a factor in your body’s ability to cool itself down, it’s important to “pay attention to the heat index—a measure of the ambient temperature and humidity,” Mark Conroy, MD, emergency medicine and sports medicine physician at The Ohio State University Wexner Medical Center, tells SELF. “For example, if the air temperature is 100 degrees and the relative humidity is 55%, the heat index will be 124 degrees,” the NWS notes. You should be cautious when the heat index hits 80 degrees; 90 degrees put you in “extreme caution” territory; and anything above 103 degrees is a danger zone.

There are other factors to be aware of, too. While “shade is helpful to reduce the additional temperature added by direct sunlight” it “does not lower the environmental temperature or humidity,” Lewis Nelson, MD, chair of emergency medicine at Rutgers New Jersey Medical School, tells SELF. Flipping on a fan creates a breeze, yes, but it “simply moves hot and humid air past your skin” and won’t help your body in the way it needs during extreme heat, Dr. Nelson says. In fact, the American Red Cross and Environmental Protection Agency note that using a fan may cause your body to gain heat once the indoor temperature reaches somewhere between 95 to 99 degrees, or above your typical body temperature.

If you don’t have air conditioning and your area is in a heat wave, you may need to consider relocating for a bit to stay safe, Dr. Pryor says. That could mean temporarily shacking up with relatives or friends or visiting a community cooling center if they’re available near you. “Your home can become a sauna without air conditioning in a heat wave,” Dr. Pryor stresses.

Another pro tip: “A trip to the library, grocery store, local pub, or movie theater can be life-saving, especially if it is not cooling off at night,” William Roberts, MD, director of the sports medicine program at the University of Minnesota Medical School, tells SELF. Because heat-related illness can happen due to heat exposure over time, getting these breaks from high temps can help lower your risk of getting sick, he explains.

What are some other safety tips to help you stay cool in the heat?

Getting into an air-conditioned space during extreme heat is the best way of protecting yourself against heat-related illness, Dr. Pryor says. But there are a few additional things you can do to try to minimize your risk if you’re not able to be in air conditioning at any given moment.

Choose your clothing carefully.

Go for lightweight, light-colored, and loose-fitting clothes (something like a cotton or linen shirt). Heavy, form-fitting clothing obviously won’t feel great when your skin desperately needs to breathe. Meanwhile, dark-colored clothes actually absorb the sun’s ultraviolet rays and can make you feel hotter, Dr. Pryor says.

Skip the electric fan when it’s really hot.

Remember, this is especially important when the indoor air temperature is tipping over 95 degrees. Using a fan could cause your body to gain heat once the indoor thermostat tips near this number. At this point, it’s important to seek out a space that provides A.C. if you can.

Focus on staying hydrated. 

Dr. Pryor says it’s tough to give a specific water intake recommendation since each person loses water via sweat in different amounts at different rates. At baseline, though, women should generally strive to have 11.5 cups of fluids a day and men should aim for 15.5 cups, per the U.S. National Academies of Sciences, Engineering, and Medicine. Beyond that, Dr. Pryor recommends paying attention to your urine. If it’s the color of lemonade or lighter, you’re good. If it’s the color of apple juice or darker, you probably need to drink more water. Another tip, per Dr. Conroy: Take it easy on alcohol and caffeinated drinks, as both can contribute to dehydration.

Shut out the sun.

If you don’t have shades or curtains, it’s not too late to invest. Natural light is a summertime perk, but curtains can help “block solar radiation from the sun from heating the air inside your home, effectively keeping your abode cooler,” Dr. Pryor says. The exact type you use is “unlikely” to make a significant difference, he adds, so use whatever works best for your home and budget.

Rethink your dinner menu. 

Your stove and oven give off a lot of heat and can make your space even steamier. Instead, if you’re able to, consider making a meal that requires no heat, like one of these no-cook dinners.

Limit your time outdoors.

If you really want to venture outside, aim to do so when the day is at its coolest, like early in the morning (Dr. Pryor’s recommended time) or once the sun starts to set.

Cut down on strenuous exercise.

“Exercise is okay if you know how to reduce the time and intensity of the workout,” Dr. Roberts says. So, if you typically run three miles, you might instead run one or two during a cooler time of the day, have water with you or nearby, and take breaks to check in on how your body feels.

Protect yourself from U.V. rays.

When you’re outside, a wide-brimmed hat, sunglasses, and broad-spectrum sunscreen with a minimum of SPF 30 will help keep your skin safe from sunburn and heat rash, both of which can make your body feel hotter. (Don’t forget to reapply every two hours if you’re cooling off at the pool or at the beach!)

Take a cool shower or bath.

This kind of has an air conditioning effect, Dr. Pryor explains. Cool water helps lower your body temperature quickly—and feels great. This is also an important tip to keep in mind if you believe you or someone near you is dealing with a heat stroke situation, which is the most serious heat-related illness, the CDC says. In this scenario, a person’s body temperature will skyrocket and they may stop sweating altogether, in addition to the various symptoms mentioned above, like a fast pulse and dizziness or confusion. If you’re showing signs of heat-related illness or your symptoms are getting worse, Dr. Pryor says it’s time to call 911 or head to the E.R.

Time is critical here: When a person is in this state, they need to take some crucial steps while waiting for help to arrive. Unneeded clothing should be removed, and they should get in a cool tub of water or in a cool shower, spray themselves down with a garden hose, mist themselves with cold water, or place some ice packs or cold, wet towels on their body—whatever method is nearby and helpful in aggressively lowering their body temperature. 

This is the situation you should strive to avoid when a heat wave hits. The key thing to remember is “staying within your heat tolerance and not taking on new activities when it is really hot,” Dr. Roberts says. “If you feel overheated, stop and find a cool spot to rest.”