Vast swathes of southern Ontario are under a heat warning that is set to continue throughout the weekend.
Environment Canada issued a heat warning Saturday morning valid for Saturday and Sunday, warning humidex values are expected to hit the low 40s.
“Maximum temperatures are expected to be in the low thirties with minimum temperatures in the low to mid-twenties, bringing little relief from the heat,” the warning said.
The heat warning was issued across the vast majority of southern Ontario, including Toronto, Ottawa, London and Hamilton.
Just five areas of southern Ontario — Algonquin, Burk’s Falls – Bayfield Inlet, Parry Sound – Muskoka, Haliburton and Grey – Bruce — were not placed under a heat warning.
The agency said, as a result of hot and humid air, the Air Quality Health Index was approaching its high-risk category.
The public are being reminded to drink lots of water and watch for the signs of heat illness, including swelling, rash, cramps and fainting.
“Outdoor workers should take regularly scheduled breaks in a cool place,” Environment Canada said.
Cooler temperatures are forecast for Monday.