Heat alert: How extreme heat affects the body

The holiday weekend won't bring us steamy temperatures, but it'll still be a good time to get out and have some fun.
The holiday weekend won't bring us steamy temperatures, but it'll still be a good time to get out and have some fun. THE CANADIAN PRESS//Dave Chidley

TORONTO – Canadians have been waiting for warm weather’s arrival, and Mother Nature has finally delivered.

But a bit too much, perhaps: In Toronto, the city’s chief medical officer of health warned of an extreme heat wave as temperatures climbed to a balmy 32C.

The erratic weather – from cold, to hot, rainy and foggy – can take a toll on our health. Rising temperatures and muggy, humid days, tamper with our heart rate, breathing and even our patience.

Read more: The heat is on in Toronto

Take a look at how extreme heat affects the body:

Changes to your heart rate: In that sticky 30C weather, your body is working overtime to cool your system. For starters, your heart picks up the pace to send blood flow to your skin – similar to when you start jogging – and in turn, you’ll sweat in an attempt to cool down. You feel tired, winded and sluggish; you’re irritable, and it seems like you can’t take a deep breath. If you have asthma or other respiratory problems, health officials suggest you stay indoors or keep away from strenuous activity outside.

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Read more: Get ready for heat and humidity in the GTA

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High temperatures can cause bouts of sickness: After some time in sizzling heat, some of us could be at risk of heat-related illnesses – heat stroke, heat exhaustion, fainting or even heat edema, when your hands, feet or ankles swell. These conditions happen if you overexert yourself while you’re outdoors, Health Canada notes.

Once your body’s internal temperature hits 40C, you could encounter heat exhaustion. Heat stroke occurs 3.5 times more often in adults who are overweight or obese, according to research published in the Canadian Medical Association Journal.

If you’re braving the excruciating heat outside to mow the lawn, walk to work or run errands, here are some signs that you may have overexerted your body: dizziness, nausea or vomiting, headache, rapid breathing and heartbeat, and even extreme thirst or a dry mouth.

Read more: Your forecast

Dehydration: With dehydration, your body is moving more water out of its cells than it’s taking in through drinking. As you’re sweating to cool down, you’re quickly shedding your body of sodium, chloride and electrolytes like potassium. These minerals keep your organs and your muscles happy. This is why experts always encourage athletes and those of us venturing outdoors to keep drinking water and refueling with drinks that have electrolytes.

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Vulnerable groups: Children, seniors, those with respiratory problems and even those who have diabetes or take medication could be more susceptible to the heat. Heat stress is most taxing on these groups because their bodies work to compensate for the heat. Young kids haven’t fully developed their bodies’ ability to regulate temperature, either.

Read more: Heart attack risks spike in the winter regardless of temperature, location, doctors say

If you need to head outdoors, try to prepare by choosing less humid times of the day – before the sun rises, or later on in the evening. It’s the midday sun that’s strongest. Wear loose, light clothing and carry a bottle of water.

If you don’t have working air conditioning or a fan at home, experts suggest heading to cool places for at least a few hours a day – malls, libraries, movie theatres or community centres could offer some reprieve and rest on your body.

Read more: Are Canadians feeling the winter blues in April?

For more on extreme heat, take a look at information on Health Canada and the Centers for Disease Control websites.

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