How you (and your home) can stay cool in a heat wave

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Ongoing heat warnings cover most of British Columbia with sweltering conditions breaking more than a dozen heat records across the province. Lytton, B.C., which was devastated by wildfires last summer during an extreme heat wave, hit 40.2 degrees on Tuesday, marking the first time B.C. temperatures have climbed above 40 degrees this year.

And last week, much of Ontario, southern Quebec and Nova Scotia were under heat warning alerts, with temperatures reaching 30 degrees or feeling as hot as 40 with the humidex in some cities.

As heat waves become increasingly common across Canada, so too does the threat of heat-related illnesses, such as heat exhaustion and heat stroke. Older adults and people with chronic health conditions, such as diabetes and high blood pressure, are particularly at risk.

Heat waves are Canada’s deadliest form of extreme weather. Do we need better warning systems?

Here is advice for how to keep yourself, your home and your pets cool during heat waves, plus information about the health risks that can be caused by extreme heat.

How can I stay cool during a heat wave?

Health Canada and local governments offer some tips on how to keep cool during heat waves, including:

• Stay hydrated. Drink plenty of liquids even before you feel thirsty to decrease your risk of dehydration. This is especially important for older people because as we age, our sense of thirst diminishes. Fruits and vegetables make for ideal snacks, since they have high water content.
• Wear loose-fitting, light-coloured clothing and wide-brimmed hats. If you’re out in the sun, bring an umbrella to block exposure.
• If your home is extremely hot, take cool showers or spritz yourself with cool water.
• If you don’t have air conditioning in your home, try to spend a few hours in a cool place such as an air-conditioned public library, a swimming pool or a tree-shaded park.

How can I cool down my non-air conditioned home?

If your home doesn’t have air conditioning, here are some practical ways to cool it down:

• Keep curtains, awnings and blinds closed during the day. If you don’t have dark blinds, block out the sun with dark blankets. According to BC Hydro, closing curtains or shades in rooms exposed to direct sunlight can block up to 65 per cent of heat that enters homes through windows.
• If it’s cooler in the evening, open your windows to let the cool air in.
• While fans won’t cool the air in a hot room, they can help keep air flowing in your home. Place a portable fan near a window in the cooler times of the day – such as early morning or evening – and draw the outside air into your home.
• Reduce drafts and seal up your doors or windows, which can bring in hot air.
• Make meals that don’t need to be cooked in an oven.
• If your home is unbearably hot, check to see where your city’s nearest cooling centre is. These are often public buildings, such as libraries and community centres, as well as swimming pools and splash pads.

In the long term, ensure any outdoor space, even just a small balcony, has some greenery. Artificial surfaces such as concrete absorb and re-emit the sun’s heat more than natural landscapes – a phenomenon known as the urban heat island effect. The difference in daytime surface temperatures between urban and rural areas can be as high as 15 degrees.

How can I keep my cat or dog cool during a heat wave?

Extreme heat can also be dangerous for our pets. Here are some ways to keep them cool:

• Walk your dog in the early morning or evening, when it’s cooler out and the asphalt is less hot. Be extra careful with dogs with white-coloured ears – they are more susceptible to skin cancer – and short-nosed dogs, who can have a harder time breathing.
• Make sure you have plenty of fresh water for your pets. If you are going to be out all day, put ice cubes in the water bowl before you head out.
• If you have a long-fur cat, give them a brushing to remove excess hair or consider a professional clipping. You can also stroke your cat with a damp cloth or paper towel, which can help cool them down.
• Consider purchasing a cooling pad, which uses water or non-toxic gels to absorb heat from your pet’s body.
• Watch for signs of heat stroke, which can include heavy panting, excessive thirst, dizziness, lack of co-ordination, vomiting and a rapid heartbeat. If you think your dog is suffering from heat stroke, the Humane Society of the United States recommends moving it into the shade or air-conditioning, applying ice packs or cold towels to its head, neck and chest or running cool water over it.

What are the health risks of extreme heat?

Muggy air, sweltering humidity and high temperatures are uncomfortable, but extreme heat can also lead to dangerous consequences, including heat exhaustion and heat stroke.

Heat exhaustion is caused by excessive loss of water and salt, and can cause heavy sweating, weakness, dizziness, nausea, headache, diarrhea and muscle cramps.

The most serious type of heat illness is heat stroke, which is the result of body heat overload. Heat stroke symptoms may include a core body temperature of 40 degrees, rapid breathing, confusion, nausea and complete or partial loss of consciousness.

“Your brain likes to be at a given temperature, so once it gets hot, it stops processing well,” said Dr. Courtney Howard, an emergency physician in Yellowknife and former president of the Canadian Association of Physicians for the Environment. “That’s a sign that the person’s body is having trouble coping.”

A lab at the University of Ottawa is currently studying the effects of rising temperatures on human health, particularly among the elderly and those living with chronic illness. Trials showed older participants not only gained heat at a faster rate, but they also saw their temperatures plateau at a higher level than the younger subjects.

Who is most at risk for heat-related illnesses?

• Elderly people, who have a weaker thirst drive and don’t sweat as readily
• People who take anticholinergic medications, which can cause dryness of the mouth and increased heart rate (Benadryl is an example)
• People with pre-existing health conditions such as high blood pressure or respiratory issues
• People with mobility issues, who may find it hard or impossible to move from a hot space to a cool one
• People experiencing homelessness or who are lower income, as they may not have access to cool spaces

If you or someone in your life falls into these categories, be sure to protect yourself and others as much as possible during heat waves. Health Canada recommends arranging for regular visits by family members, neighbours or friends who can help identify signs of heat illness.

If you are experiencing any heat illness symptoms, move to a cool place and drink liquids right away. If you are with someone who is showing symptoms, fan the person as much as possible, move them to a cool place and apply cold water to their skin or clothing. Heat stroke is a medical emergency, so call 911 immediately if you are caring for someone “who has a high body temperature and is either unconscious, confused or has stopped sweating,” says Health Canada.

With files from Kathryn Blaze Baum, Ivan Semeniuk, Matthew McClearn

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