Ontario sizzles as extreme heat wave continues for Canada Day

Beth Macdonell has more on the measures being implemented to keep sun seekers and vulnerable people safe as Toronto remains under a heat warning.

As much of Ontario swelters through Canada Day, advocates warn that vulnerable populations are at the greatest risk from the extreme heat.

Orange heat warnings are blanketing Environment Canada’s weather map, stretching from Windsor to Toronto to Ottawa.

The weather agency said those southern areas can expect temperatures of up to 37 C.

In Toronto, Environment Canada calls for a high of 34 C with humidex values near 44. The weather agency also calls for a 40 per cent chance of rain with a risk of thunderstorms early Wednesday evening.

There are also heat warnings in place for northern Ontario, where places like Sault Ste. Marie, Timmins and Thunder Bay could see temperatures of up to 33 C, with humidex values near 40.

Keith Hambly, CEO of Fred Victor, a Toronto-based organization that provides shelter, housing, and support services across the city, says it is important for all community members to support one another.

Fred Victor has a “Keep Cool” outreach team that helps unhoused residents during heat waves. The team deploys whenever the city issues a heat warning, checking on people at known hot spots across the city, including parks and areas near shelters, and distributing water and sunscreen. They can also point people toward free cooling spaces run by the city and other agencies.

Hambly says some other populations are at an increased risk during heat waves, such as the elderly or people who live alone and have minimal connections outside of their own space.

“It’s important that anybody in the city of Toronto be a good neighbour and check in on people,” he said.

Heat can be especially dangerous for people who are chronically homeless, Hambly said, since many already face what he called “premature aging,” meaning health conditions more typical of someone decades older, including diabetes and heart issues.

He added that people on medication face extra risks, since many prescriptions are meant to be taken in a temperature-controlled setting. “If you’re constantly outside taking those medications, it can impact people very severely,” he said.

The recent closure of supervised consumption sites in Ontario also means that people who once used drugs under supervision are now doing so on the street.

Combined with an increasingly toxic drug supply, Hambly said it’s unclear how extreme heat affects people using drugs outdoors.

“We don’t know what the impact of excessive and exposed heat could be on the body,” he said.

Environment Canada said the hot and humid conditions across the province could last through the weekend.

Health experts say anyone spending time outdoors today should limit alcohol consumption, as it increases dehydration and raises the risk of heat-related illness such as heatstroke.

This report by The Canadian Press was first published July 1, 2026.