Southern Ontario will see some of the hottest temperatures of the summer over the next 72 hours, leading to heat alerts being issued by Niagara Region Public Health and many municipalities.
Brock University Kinesiology Professor Stephen Cheung, one of Canada’s foremost experts on how extreme weather conditions impact the body, says caution needs to be taken by athletes and everyone else headed outdoors this weekend.
“The biggest problem right now is the humidex,” says Cheung, who runs a research lab at Brock that is able to simulate temperatures ranging from -30 degrees to +50 degrees. “When the humidex is high, you can be sweating a lot, but it’s not really evaporating and helping you lose heat. It’s just dripping off you and making you uncomfortable.”
The inability to efficiently cool your body’s core temperature can be extremely dangerous, he says, especially for people working out and generating even more internal heat than people simply outside in the sun.
“From a physical perspective, it’s a lot more difficult to cool yourself down than when you’re in a hot, but dry environment,” Cheung says. “There’s not a lot you can physically do. If you just pour water on your skin, it might make you feel better for a brief period, but it’s not actually helping you.”
The professor’s recommendation is to keep workouts indoors during extreme heat. But if you must head outside, find shade if you can, drink plenty of cold water while exercising, and take frequent breaks.
“If you are working out in extreme conditions, don’t try to train or exercise as hard as you normally might,” he said.
The advice is also important for families headed to a park, backyard or local beach.
“Plan appropriately to not be out as long, reduce your level of exposure to the sun and the amount of activity you do,” Cheung says, adding that drinking lots of cold water is key even if you’re just lounging around.
He also encourages everyone to wear sunscreen.
“If you’re getting sunburned, your skin and sweat glands aren’t able to work as well,” he says. “Reapply sunscreen more regularly because you’re sweating more and it tends to wash it off more quickly.”