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.”
Related:
Last June, sweltering hot weather made life miserable for people across British Columbia. The week-long “heat dome” was so named because high atmospheric pressure trapped stifling air in place. It contributed to at least 595 deaths—and possibly as many as 740. Climate change makes extreme events like this more likely in communities across Canada; in coming years, we can expect to suffer through hotter, longer and more frequent heat waves.
And they’re dangerous. Older people, who may have poor circulation or underlying medical conditions, are at higher risk of overheating quickly. So are babies and small children, who don’t sweat as much as adults. Other at-risk populations include those experiencing homelessness, addictions or mental illness.
But even healthy younger adults can run into problems, particularly if they work or exercise outdoors or don’t have air conditioning at home. A full 30 per cent of the heat dome-related deaths last year were in people under 70. “My apartment in Vancouver was incredibly hot,” recalls Sarah Henderson, a 46-year-old scientific director of environmental health services at the BC Centre for Disease Control. “I slept on my balcony. People were sleeping in the parking lot of my building!”
Our country’s annual temperatures are rising two to three times faster than the world average, yet we Canadians still seem more accustomed to harsh wintry conditions than to summer weather. Here’s expert advice on how to stay cool in extreme heat.
It may sound obvious, but it’s important to regularly check a weather forecast app so you’re not caught off guard. “It could be a full 10 degrees hotter one day than it was the day before,” says Dr. Heejune Chang, a medical officer of health at the Winnipeg Regional Health Authority. “If there’s a forecast for an extreme heat event, it’s usually reported at the start of the day.”
Knowing there’s heat ahead will help you choose what to wear and plot out your day’s activities. You might pick an earlier time to go jogging, before the sun is directly overhead, or exercise indoors on the treadmill. You may even decide to juggle your job duties differently that day. “If you work outdoors all day, you’ll need more breaks to rest and hydrate,” says Chang.
If you have a loved one or neighbour who lives alone and without air conditioning, particularly someone who’s vulnerable, reach out before they run into trouble. Invite them to stay with you, or make plans to take them somewhere cool.
Find out what it was like on one of the hottest days in Canadian history.
The wrong clothing can trap both heat and perspiration, says Dr. Mark Leung, director of the University of Toronto’s enhanced skills program in sport and exercise medicine. “Avoid waterproof fabrics, which aren’t breathable. And don’t wear cotton unless you can keep changing your shirt after it soaks up sweat. Otherwise it acts as a barrier and reduces the efficiency of losing heat by sweat.”
Wear clothes that are loosely woven, lightweight and a relaxed fit for better air flow. Sportswear labelled as “fast drying” or “quick dry” is designed to wick away sweat; some high-tech clothing even includes nanoparticles for UV protection.
“Our heads are where we gain and lose a lot of heat,” Leung adds. Just as you might cover your head with a toque in winter to conserve warmth, shielding it with a beaked or widebrimmed hat in summer can reduce the amount of radiant heat your head absorbs from the sun.
The parasol has never taken off in Canada as a must-have summer accessory, but perhaps it’s time to reconsider. “That would provide a barrier, especially if it’s completely opaque,” says Leung. A 2020 experiment at Japan’s Daido Institute of Technology showed that the temperature under a parasol can be cooler by several degrees.
Here are more practical tips on how to beat the heat this summer.
A whopping 96 per cent of the people who died from B.C.’s 2021 heat dome became overheated in a residential setting. Although air conditioning is the best way to keep our homes at a comfortable temperature, almost 40 per cent of Canadian homes didn’t have even a window unit in 2019, let alone a central-air system.
Henderson points out that our houses and apartment buildings are designed to hold on to heat. “We have Canadian winters, so we insulate our homes and use double-glazed windows,” she says. “Once we warm up a place, it stays warm.” During an unrelenting hot spell, the indoor temperature can rise with each passing day. Turning on your oven or another appliance that gives off heat will worsen it.
A crucial way to keep your home from heating up is to stop the sun from shining directly on the windows. Close the curtains during the day, or install awnings or plant shrubs that block the windows. You can buy shade screens for your patio that can be rolled down to keep the sun from hitting the glass doors.
If you use an air conditioner, set it to between 22 and 25 C. At night, when it’s cooler outside, shut off the unit and open your windows instead. Use exhaust fans when you shower, to get rid of humidity, and when you cook, to get rid of heat. These tips will help save you money and use less energy.
Learn 20 tricks to keep your house cool without air conditioning.
Water is vital to keeping your body cool, and in hot weather you’ll need more of it because you’re sweating. On a regular day, most healthy adult women need about two litres of water, and men need three. Your requirements during an extreme heat event will be higher.
“You also need to drink more frequently than you normally would,” Chang says. “You can’t just guzzle water in the morning and decide you’re good to go.” Otherwise your body won’t be able to maintain the constant level of hydration it needs to function properly.
Stop and drink water even if you’re not feeling thirsty yet. “That sense of thirst in your mouth is a late sign and means you’re already dehydrated,” says Dr. Finola Hackett, a family physician working in Alberta and Yukon.
Another clue you’re not drinking enough: your urine is darker and you aren’t going to the bathroom as often, because your kidneys are working hard to concentrate what fluid is available in your body. Subtler signs of dehydration, such as trouble concentrating on your work or feeling tired, might go under your radar.
Don’t rely on beer or coffee to shore up your fluid levels. “They can both be dehydrating over time. Water’s best,” says Chang. “Athletes training in hot weather might consume drinks with electrolytes, but the general public doesn’t need them.”
Cooling off isn’t an instant process, even in an air-conditioned environment. Researchers at the University of Ottawa recently developed the world’s only chamber that measures body temperature all the way to the core, and they have reported that it can take hours for the heat stored in our bodies to dissipate completely. If you spend your day outdoors, a 10-minute break in the shade may not be enough. Once you step back into the sun, you’ll quickly warm up again.
Try to stay out of the heat for several hours a day. During hot weather, many municipalities open up cooling centres—indoor, air-conditioned public spaces. You can also seek out a library, community centre or mall.
“Even outdoors, if you’re in the shade, at least you’ll get that air movement,” says Chang. You will also feel cooler because the sun’s radiation that your skin would normally absorb is blocked. Patio umbrellas containing UV-blocking properties may be especially effective at producing comfortable-feeling shade.
A park or wooded area also offers abundant shade, as well as a reprieve from pavement and asphalt. These surfaces tend to absorb the sun’s heat and create what’s known as an urban “heat island,” raising the air temperature by as much as 4 C.
Here’s the difference between heat exhaustion and heat stroke.
Cooling yourself for a good night’s sleep is critical, says Hackett. “It’s our body’s chance to recuperate and do repairs.” Although it’s not fully understood why, quality sleep at night helps us cope better with hot days.
Unfortunately, homes that heat up during the day don’t necessarily normalize at night, even if the temperature falls outside. After B.C.’s extreme weather last year, Henderson and her research team analyzed temperature readings collected by Ecobee, a Canadian maker of smart thermostats. Many fatalities had occurred overnight, and Henderson discovered that the temperature in these homes peaked four hours after the peak outdoors. “At 9:00 or 10:00 p.m., that’s when it was hottest in the home,” she says. “So trying to reduce that heat exposure at night is probably more useful than during the day.”
In the early evening, as soon as it gets cooler outside than inside, create a cross-breeze in your home. Open a window at each end of the house to keep air moving through. A fan placed at each opening will help pull the outdoor air in and push the indoor air out.
A cool shower or bath, or a damp towel around your neck, may offer some relief at night. You can also buy special “cooling pillows,” which are designed to improve air flow and wick away sweat.
Seek out the coolest part of your home for sleeping, like a basement if you have one. Or you can do what Henderson did and snooze on the balcony or in a backyard tent. “It may still be 23 degrees outside, but that may be a heck of a lot cooler than inside your house,” she says.
Signs that the body’s self-cooling system is failing can include a headache, vomiting, pale skin, fainting, irritability and weakness. Eventually, heat stroke can occur: the person might be confused or drowsy. They may have a racing pulse, and their skin may be hot and dry.
At the earliest signs of trouble, bring an overheated person into a cool building or shade. Give them water to drink and have them lie down. Cool them off by removing any excess clothing and immersing the person in cold water, if it’s available.
Dr. Mark Leung offers this quick trick for heatstroke: “Place ice packs in all the folds of the body— the armpits, the groin, around the neck. These areas have direct access to the network of blood vessels and will help you cool down the core body temperature.”
Heat stroke is a medical emergency. It can be fatal or cause permanent organ damage. If the person isn’t improving or their symptoms worsen, call 911.
Here are 20 more symptoms you should never ignore.
Things to avoid doing during sweltering weather:
- Don’t knock back too much water too quickly. Drinking more than 1.4 litres an hour—about three regular bottles of spring water— can dilute your sodium levels and lead to confusion and seizures.
- Don’t underdress in order to cool off. Although it may seem counterintuitive, cover up. “Loose-fitting pants and long-sleeved shirts can have a cooling effect, versus your skin being directly under the sun,” says Dr. Finola Hackett.
- Don’t use fans if the air in the room is hot and the windows are closed. A fan will blow the suffocating air around, but it won’t lower the temperature. In fact, the fan’s running motor might make a room even hotter.
- Don’t respond to a 30-degree forecast in May the exact same way you would in August. “If it’s an unusually hot day early in the season, the risk of heat exhaustion is up, because your body hasn’t acclimatized after winter,” says Dr. Heejune Chang.
The hypothalamus acts like a thermostat and controls the body’s response to heat by sending signals to the circulatory system, glands and other areas. Extreme Heat Risk: Disabilities that affect the brain and nervous system, like Parkinson’s disease or spinal cord injuries, can prevent the hypothalamus from regulating body temperature.
Heart and Bloodstream
Blood vessels dilate, and the heart pumps blood closer to the skin to release heat. Extreme Heat Risk: Higher demand on the cardiovascular system can increase risk for people with heart conditions.
Lungs
Exhaling is another way the body releases excess heat. Extreme Heat Risk: Hot weather worsens air pollution, aggravating symptoms for people with issues like asthma or chronic obstructive pulmonary disease.
Kidneys
When sweating causes fluid levels to drop, the kidneys try to conserve more water by concentrating urine. Extreme Heat Risk: When the body is very dehydrated, the resulting low blood pressure and highly concentrated urine compounds can damage these sensitive organs.
Skin
Some of your body heat is used to evaporate sweat from the skin’s surface, which cools the body down. Extreme Heat Risk: In humid weather, sweat won’t evaporate as efficiently because there’s already so much moisture in the air.
Humans aren’t the only ones who suffer in hot temperatures. Dogs can get heat stroke, and so can cats and other pets. Many safety guidelines for people—limit outdoor time, drink water, seek shade—are applicable to pets, as well. Here are some more tips:
- Never leave a pet unattended in a car, where temperatures can climb quickly. Be mindful of the heat in your home, too, if they’re going to be on their own.
- Brush your cat or dog’s coat to promote better air circulation, but don’t shave them. Their fur slows down their absorption of heat from the air.
- Keep pets with medical conditions, or those who are older or overweight, out of the heat as much as you can.
- No air conditioning? You can buy cooling products, like vests and mats, that, after being pre-soaked, slowly release evaporated water to help your pet chill indoors.
- Use a spray bottle to give your pet bird a gentle misting.
- Clean the cages of smaller creatures often, and throw away untouched food, so bacteria doesn’t have a chance to grow in the heat.
Now that you know how to stay cool in extreme heat, check out 13 tricks to save on summer utility bills.
Originally Published: May 31, 2022
Originally Published in Reader's Digest Canada