Summer really is getting hotter — how to prepare and stay cool

Summer is officially underway, and with it comes extremely hot temperatures. At least 65 million Americans across several different US states experienced an extreme heat event above 100 degrees Fahrenheit in the past month.

An extreme heat event — also known as a heat wave— generally refers to a period when temperatures are much hotter or more humid than average. The federal government defines it as “a period of high heat and humidity with temperatures above 90 degrees for at least two to three days,” though that may vary depending on the specific region.

These hot temperatures aren’t going anywhere. As the planet warms, scientists predict they will become more severe and frequent. Inverse spoke with a wide range of experts from public health and disaster experts to HVAC specialists to help you prepare for extreme heat this summer.

What happens to the body during a heat wave?

Extreme heat brings with it an increased likelihood of death and illness from heat stroke and dehydration. Certain populations, such as the elderly, people who live alone, pregnant people, individuals with disabilities or chronic medical issues, athletes, people working outdoors, and children, are particularly vulnerable to extreme heat.

“An older person has impaired abilities to lose heat,” Glen Kenny, research chair in heat strain monitoring and management at the University of Ottawa,” tells Inverse, referring to a condition known as hyperthermia, in which the body cannot regulate heat properly.

The hotter it gets outside, the greater the risk of heat stroke.

“During heat stroke, body temperature regulation is disrupted, which causes fever, reddening of the skin, dizziness, and increased heart rate and respiration,” Rosmy Barrios, a medical content author at Health Reporter and regenerative medicine specialist and head of anti-aging at the Internal Medicine clinic in Serbia, tells Inverse.

Normally, we take in heat from the environment and it evaporates through our sweat which allows us to maintain our core body temperature. “In a hot environment where it's a heatwave, your body's actually gaining heat from the environment,” Kenny says. So, your body has to work even harder to sweat more to stay cool. That becomes a problem in humid environments, where the sweat sticks to your skin and doesn’t evaporate, literally preventing you from cooling off.

How to prepare for extreme heat

Extreme heat can be deadly and systemic policy changes are crucial to preventing it, but you can reduce some of the individual risks through basic preparation.

If you have air conditioning, change the filter frequently

Anthony Perera, founder and Chief Growth Officer of Air Pros USA, a heating, ventilation, and air conditioning (HVAC) repair and service company, tells Inverse:

"One of the most important things we tell customers is to regularly change the filter on their A/C unit. The standard recommendation is 2 to 3 months with a good HEPA filter, but changing them more often when you’re using your heating/air conditioning unit frequently in your home and immediately after a summer storm will make it easier for your A/C unit to cool the home.”

Keep blinds closed during the day – and consider investing in blackout shades

Several of the experts we interviewed suggest keeping the blinds closed during peak daytime hours. Less sunlight filtering into your home translates to lower temperatures, and lower energy bills.

Blackout shades, which are designed to block out light from your windows, may be particularly helpful. Kyri Baker, an assistant professor of building systems engineering at the University of Colorado Boulder, tells Inverse that blackout shades prevent the sun “from entering your house during peak hours,” especially on the south side of your home which gets the most sun.

“For longer-term preps, people should think about modifying their homes to block southern sun from hitting their house and thus heating up inside,” John Ramey, founder of The Prepared — a resource and community offering tips to prepare for emergencies and life disasters like extreme heat — tells Inverse.

“A cheap improvement is adding screens, window locks, and whatever other gear is needed to leave the right windows open for airflow moving through the house,” Ramey says.

Use fans strategically

While fans are often suggested for those without air conditioning, Kelly says that at temperatures above 95 degrees Fahrenheit, a fan simply won’t be enough. It doesn’t “provide the appropriate benefit to protect against rises in core [body] temperature.”

He adds that a fan wouldn’t do much to protect vulnerable people like elderly individuals in extreme heat and “provides relatively little benefit relative to air conditioning.”

That being said, a fan is still a good option for more modestly warm weather. Mark Woodruff, Senior Product Manager at Trane Residential — a company that sells HVAC products — tells Inverse that running a ceiling fan counter-clockwise will “create a downdraft of cool air” to help you keep temperatures lower in the summertime.

No A/C? A DIY air conditioner might help

Davin Eberhardt, founder of Nature of Home, has expertise in home redesign and has been an electrician with the International Brotherhood of Electrical Worker since 2004. Eberhardt suggests taking a bucket of ice and cutting holes out of the sides, then placing a portable fan on top to make a DIY air conditioner.

Consumer Reports tried it out and found it can lower temperatures by two to three degrees — though they also noted temperatures began rising again about 30 minutes afterward, so it’s not effective over a longer period. Here’s Consumer Reports’ own video explaining how they built their device. An easier hack might be to simply place a bowl of ice in front of a portable fan. Apartment Therapy has a great how-to guide on that.

Open windows at night

“If you live in an area where it's cooler at night, opening your windows at night keeps the thermal mass of your house cold for longer,” Baker says.

Ramey adds that installing window screens and locks would be a good idea. That way you can keep your home cool by opening windows but also keep your home secure.

Kenny says that cross-ventilation can also help keep homes naturally cool. Cross ventilation refers to the practice of keeping windows on both sides of a building open, allowing wind to push cool air into the home through the wind-facing side and pushing out warm air through the window on the other side of the building.

How to stay cool (indoors and outdoors)

In general, Barrios says that “outdoor activities should be restricted if the temperature exceeds 90˚ F, as there is an increased risk of heat stroke.” Not everyone has the option to stay indoors during a heat wave, however. Shayne Stevens, Senior Corporate Director of Rosendin — an electrical contracting company that requires employees to partake in trainings to recognize and prevent heat illness — offers a few tips:

• Stay hydrated by drinking water regularly and taking regular breaks when possible.
• Avoid high-sugar and caffeinated beverages like energy drinks.
• Do the most physically demanding work earlier in the day when temperatures are cooler
• If you don’t have access to shade, consider relatively low-cost outdoor ventilation options like portable fans or misters
• Use a buddy system so you and your coworkers can check in on each other and schedule breaks together.
• Pay attention to signs of heat illness like heavy sweating, cramps, weakness, and dizziness

“It’s important to let your body adjust to the heat by limiting exposure in the beginning, taking more breaks, and hydrating,” Stevens says.

Drink water — a lot

During extreme heat, your body can lose fluids very quickly, leading to dehydration.

“The heart has to work hard when someone is exposed to increased heat because your body has to pump more blood to keep continuous evaporation through the skin,” Kari Nadeau, an environmental health expert and Director of the Sean N. Parker Center for Allergy and Asthma Research at Stanford University, tells Inverse.

Barrios says it’s a good idea to drink mineral water because the “human body loses a lot of fluids and minerals through sweat.”

If you’re working in the heat, Nadeau says a good rule of thumb is to drink one cup — 8 ounces — every 15 to 20 minutes.

“Drinking at shorter intervals is more effective than drinking large amounts infrequently,” Nadeau explains.

Move slower

Barrios says you should move more slowly than usual during extreme heat. Moving around causes your body to produce even more heat, which you need to evaporate through sweating and breathing.

Wear sunscreen and find shade

This one should be a no-brainer. Protect your skin from long-term damage while staying cool. Sunburns can also impair the functioning of your skin – which is crucial to maintaining heat loss.

Place cold towels or ice on the wrist, neck, and forehead

“I would advise holding ice cubes or a cold compress on your wrist for five seconds every couple of hours,” Barrios says, though she says that placing cold compresses on the neck and forehead can also help cool you down.

“Just be careful not to do this for a long time to avoid freezing your skin,” Barrios adds.

Limit cold showers

Although your brain might tell you to take a cold shower as temperatures rise, this might not help you stay cool in the long run.

“It might be counterintuitive, but taking a very cold shower or sitting right in front of a powerful AC can make things worse,” Ramey says.

While you’ll temporarily feel better, Ramey says your body will respond “by drawing blood away from your skin and towards your core — which will make it harder to sweat and cool down when you go back out into the higher temperatures.”

Sit in the lowest level of the home

Kenny says that staying in the basement during extreme heat is a good idea, because it tends to be cooler there than on the ground level.

Adelle Monteblanco, an assistant professor in the Department of Sociology at Middle Tennessee State University, agrees. Monteblanco’s research focuses on the intersection of health, gender, and environment.

Monteblanco tells Inverse: “The lowest level of a home should be the coolest; for example, a basement is often much more comfortable than the outside air.”

If you don’t have a basement, remain on the lowest level of your home during a heat wave.

Wear loose clothing

Wearing lighter, loose-fitting clothing (darker colors tend to absorb more heat) can help you stay cool, says Ramey.

Limit exercise outdoors

“Forget your routine if you don’t want to experience heat-related consequences. If you can’t stand a day without exercise, plan your workouts until 10 a.m. to avoid the heat,” Barrios says.

“We suggest avoiding exercising in hot weather until it has cooled off to lower than 80 [degrees] Fahrenheit,” Nadeau adds. If you work out indoors, remain in a cool space in your home.

Know the signs of heat stroke

“Heat stroke is the most serious heat-related illness. It occurs when the body can no longer control its temperature: the body's temperature rises rapidly, the sweating mechanism fails, and the body is unable to cool down,” Nadeau says.

It’s not always easy to spot signs of heat illness, and elderly people are often less reactive or

responsive to recognizing something is wrong than younger people.

But he says there are some general warning signs you should keep out for:

• Thirst
• Feeling shaky or disoriented
• Slurred speech or confusion
• Malaise — a general feeling of discomfort
• Stomach upset/nausea

“Remember to check in on your neighbors and family members,” Samantha L. Montano, Assistant Professor of the Emergency Management Department at Massachusetts Maritime Academy and an expert in disaster preparation, tells Inverse.

Montano says you should plan to help get elderly individuals and neighbors to cooling centers during heat waves if they need assistance. She adds that the elderly are “especially vulnerable during extreme heat not only because they're more likely to have health issues and be on fixed incomes, but because of social isolation.”

“Most [elderly people] will feel okay for the most part and it hits them suddenly,” Kenny says.

Prepare before riding public transit

Not everyone has access to a car, so if you’re taking public transit, you’ll need to find manageable ways to stay cool on the go. Find shade and hydrate whenever possible.

But the best method may depend on whether you’re experiencing dry or humid heat, because the body cools itself in different ways in each setting. In arid heat, evaporative cooling (a fancy term for sweating) is more effective.

“For instance, in a hot and dry climate like Phoenix, evaporative cooling works best, so it could help to carry a spray bottle with water,” Yuliya Dzyuban, a postdoctoral fellow at Arizona State University’s Urban Resilience to Extremes Sustainability Research Network, tells Inverse.

On the other hand, “on a hot and humid day in Atlanta, it would be best to carry a small fan, since the wind would be more important when the evaporative capacity of the body is limited by high humidity.”

If possible, you should also want to avoid the bench at the bus stop. Dzyuban says “it might not be a good idea to sit on a metal bench” because sun-exposed surfaces like metal and asphalt “can get sufficiently hot to burn the skin.”

Ask for workplace accommodations — and consult a legal hotline if needed

Not all workplaces have accommodations for extreme heat. Workers — especially people vulnerable to heat like pregnant individuals — may need to ask for accommodations, but could be hesitant to do so.

“I’d hate to hear that pregnant people are avoiding asking for a simple accommodation —e.g., water, a stool – for fear of being fired,” Monteblanco says.

If you have questions about legal rights to workplace accommodations for pregnancy and other medical conditions, A Better Balance — a national nonprofit advocacy organization helping pregnant workers and caregivers — offers a free legal hotline.

Steven says employers of outdoor workers should encourage employees to take breaks during extreme heat by setting up water and shade stations close to their place of work.

Tips for general emergency preparedness

Help your elderly neighbors and family members

Massachusetts Maritime Academy’s Montano says you should plan to help get elderly individuals and neighbors to cooling centers during heat waves if they need assistance. She adds that the elderly are “especially vulnerable during extreme heat not only because they're more likely to have health issues and be on fixed incomes, but because of social isolation.”

Kenny says that elderly individuals, due to physical constraints, may have a harder time practicing some common-sense measures during a heat wave, like cooling oneself with towels or ice. If you have elderly family members — especially those living alone or far away — consider implementing some of the previous tips we discussed to get their home ready for extreme heat events, especially if they have mobility issues.

Kenny adds that this preparation might be as simple as providing a cool space in a basement — where it’s typically less hot than ground level — where older individuals can watch TV, installing a thermostat that you can monitor remotely if temperatures get too high, or finding low-cost ways to prevent sunlight from entering the home, such as covering the windows with cardboard.

Prepare ahead

Keep a good supply of drinking water, shelf-stable food, and a “go bag” on hand.

It’s always good to have supplies in case the power goes out during an extreme weather event or if it’s too hot to venture out for groceries.

“One of the most critical, universal preps is to have potable water stored in your home ahead of time,” Ramey says, adding “this can be helpful in a blackout, heatwave, or anything really.”

Montano adds that having a go-bag of your essential items in case you need to leave your home to go to a cooling center is a good idea. The Sierra Club has a handy list of items to include a go-bag, but some typical items would include food and water, batteries and a phone charger, and a first-aid kit.

Don’t forget about your pets

José Arce, President-Elect of the American Veterinary Medical Association, told Inverse in 2021 that “if it’s hot for you, it’s even hotter for your pet.” So if you’re feeling sweaty, you should check up on your pets to make sure they don’t develop heatstroke. We also published an article with tips on how to cool down an overheated dog.

Locate your nearest community cooling center

In recent years, cities have set up cooling centers as emergency shelters for people who cannot afford to install cooling devices at home or need to escape the heat outdoors. These are often schools, libraries, or community centers that are accessible to the public. Check your city or town’s website or social media pages to find your local cooling center.

“Community cooling centers are a great resource that more people should use,” Ramey says.

Not everyone has the financial means to modify their home, so they may need to leave the house to escape the heat. If your town does not have a cooling center or if it is not conveniently accessible, consider other places like malls or movie theaters.

Set up your phone for emergency alerts

The National Weather Service automatically issues wireless emergency alerts in cases of natural disasters and extreme weather events, and local offices will typically issue heat advisories if the temperature is expected to exceed 100 degrees Fahrenheit for two or more days. You can typically check to see if your phone is set up to receive alerts by going to your phone’s settings and clicking on the “notifications” tab.

But other state and local officials may send heat advisories as well through social media and alerts.

“You should check your city/town website to see if there is an emergency alert system you can sign up for,” Montano says.

Montano adds, “You should also follow your city, emergency management agency, and other official local sources on social media.”