Heat warnings remain in effect across Ontario. Here's what you need to know

Environment Canada says a heat warning remains in effect today for southern Ontario and parts of northern Ontario.

According to the agency, temperatures are expected to reach the thirties, with some areas feeling warmer due to humidity.

The warning applies to Hamilton, Toronto, Niagara, London, Halton-Peel and other regions in southern Ontario, as well as Greater Sudbury, Kirkland Lake and North Bay in northern Ontario.

In the Toronto area, Environment Canada is also reporting risks of thunderstorms developing in the early afternoon.

The heat event has brought hot, humid air to Ontario, which poses a risk to air quality. 

High temperatures and poor air quality can be risky for vulnerable individuals, such as young children, pregnant women, older adults or people with chronic illness, EC said. It can also prove a danger to those working or exercising outdoors.

“Never leave people or pets inside a park vehicle,” the agency said. “[and] when it’s hot, eat cool, light meals.”

Outdoor workers could take regularly scheduled breaks in cool places, they added.

Cooler temperatures can be expected Thursday, the agency says.

With files from The Canadian Press.