Temperatures in Toronto are set to hit the low forties when combined with humidity Sunday as much of southern Ontario remains under heat warnings issued by Environment Canada.

Overnight, temperatures will drop to the mid-twenties, they say. Cooler temperatures are forecasted for Monday.

Heat warnings are currently in place across much of southern Ontario, from Ottawa to Barrie to Windsor.

heat warnings map

INCREASED RISK OF HEAT ILLNESSES

Environment Canada is warning residents that the risks brought on by heat are greater for young children, pregnant women, older adults, people with chronic illnesses and people working or exercising outdoors.

“Heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion,” the agency says.

They advise drinking plenty of water, checking in on family and friends, never leaving people or pets inside vehicles, and taking regular breaks if working or exercising outdoors.