‘Multi-day’ heat wave alert issued for much of Ontario

Older people, children and others at increased risk of heat-related illness are urged to take extra caution during a “multi-day” heat wave alert issued for Ontario.

Environment Canada said the heat warning is expected to last until Thursday for most of the province, including the Greater Toronto Area.

It said the actual temperature is expected to fluctuate between high 20s and low 30s, with a humidex of high 30s to low 40s.

The weather agency said while the extreme heat will affect everyone, it will pose greater risks to young children, pregnant women, older adults, people with chronic illnesses and those working outside.

“It is important to note that it is dangerous for at-risk populations,” said Trudy Kidd, a meteorologist at Environment Canada. “We do tend to get heat warnings in the summer, and it is just at the point where people need to take special care.”

Canada’s weather agency said it issues heat warnings when high temperatures pose an “elevated risk” of illnesses such as heat stroke or heat exhaustion.

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Kidd said drinking water or other liquids and staying in cool places are “super important” during the heat wave.

Those who don’t have access to an air conditioner should seek out air-conditioned spots such as shopping centres, libraries, community centres, or friends’ and family’s homes, she said.

“(If) mobility is an issue then another option could be taking cool showers or cool baths until you feel refreshed.”

She cautioned Ontarians not to leave people or pets inside parked vehicles.

“If you are a healthy individual and you’re used to the heat and this is no problem for you, it would be important to … visit your neighbours, friends, and older family members that may have those chronic illnesses,” Kidd said.

Rafi Aaron, a spokesperson for Interfaith Coalition to Fight Homelessness, said the current heat wave impacts Toronto’s homeless population more than other groups in the city, calling it an “emergency situation.”

1:48 Peterborough Regional Weather Forecast for July 4, 2023

“It is just not a matter anymore of having cooling centres in the summer and warming centres in the winter,” he said.

“In the last 10 days, when twice Toronto had the worst air quality in the world, people were told not to be outdoors. But if you’re unhoused, you have to be outdoors.”

Environment Canada said people who live near Ontario’s lakes may see some reprieve from the heat as temperatures in those areas tend to be cooler thanks to lake breezes.

“Lakes tend to take a while to warm up, whereas the land we live on can heat up quite quickly with the sun,” Kidd said.

‘One of the warmest and most humid stretches’ so far this year

Global News meteorologist Ross Hull said the current heat wave in southern Ontario is “one of the warmest and most humid stretches the area has seen so far this season.”

“The warm and humid weather will last into Thursday, but by Thursday evening it looks like a cold front will swing through bringing showers and the risk of thunderstorms,” he said.

“In the wake of the front, it won’t be quite as hot and humid heading into the weekend, with temperatures staying in the high 20s with humidex values dropping to the low 30s.”

— With files from Global News’ Ryan Rocca