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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.
How to Stay Cool and Safe in Extreme Heat According to Experts
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When a heat wave hits and persists, it can feel nearly impossible to stay cool, even with the AC on blast. So you’ve probably felt excessively sweaty, exhausted, or cranky (or a lovely combination of the three) at some point this summer, especially in the last few weeks. July has likely been the hottest month on record, experts say, and many parts of the US are still in the thick of the sweltering stickiness.

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 about the importance of being safe in scorching conditions, citing “widespread heat advisories and excessive heat warnings.”

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 (and cool) when temperatures in your area start to reach potentially dangerous highs.

First, let’s talk about how extreme heat can affect your 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.”

Humidity makes hot temperatures feel much worse.

The National Weather Service (NWS) points out that a combination of high temperatures and high humidity often fast-tracks the road to heat-related illness.

“Our bodies have a great natural cooling system,” Henry Young, MD, a clinical associate professor of emergency medicine at The Ohio State University Wexner Medical Center, tells SELF. “When your body begins to warm up, it releases water and salt [and other electrolytes] in the form of sweat. Your sweat can then absorb the heat from your body.” Then it slowly evaporates. “This removes heat from our bodies and makes us feel cooler,” Dr. Young says.

But the rate at which sweat evaporates depends on how much water is already in the air around you. “If it is a day with little water in the air, or low humidity, then the sweat will evaporate faster,” Dr. Young says. “If it is a day with a large amount of water in the air, or high humidity, then the sweat will evaporate slower. This means on days of particularly high humidity, it may be more difficult to stay cool.”

If your body has a hard time naturally cooling itself, your core temperature can start to rise—and that puts you at risk of developing a heat-related illness, Bert Mandelbaum, MD, sports medicine specialist and orthopedic surgeon at Cedars-Sinai Kerlan-Jobe Institute in Los Angeles, tells SELF. “In addition, profuse sweating without replenishing fluids will eventually deplete the body of necessary electrolytes.”

It’s really hard to get reasonably cool without air conditioning, especially in stifling heat.

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.

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. Though “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 shirt or linen pants). 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 AC if you can.

Focus on hydrating, even before you go outside.

“If you are going to be outside in high heat, start hydrating early,” Dr. Young says. And if you know you’ll be out in the heat for a while, he recommends having a food or beverage that contains electrolytes—say, a salty snack or sports drink—before you head outdoors, since the odds are high that you’ll lose a lot of them in your sweat. You need both water and electrolytes to maintain adequate hydration because minerals like sodium and potassium help keep fluid in your body’s cells, as SELF previously reported.

Keep tabs on how much water you’re drinking.

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 US National Academies of Sciences, Engineering, and Medicine.

You likely reach for water when you feel parched but staying on top of hydration is crucial in hot and humid conditions, so keep sipping even when you don’t feel thirsty. (Having a reusable water bottle nearby can help a lot when you need the reminder.)

Dr. Pryor recommends paying attention to your pee too. 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.

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.

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.

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 UV 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 emergency room.

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.”