A heat warning has been issued for parts of Muskoka.

Environment Canada is issuing the advisory for Bracebridge, Gravenhurst and Port Carling.

The weather agency is forecasting daytime high temperatures in excess of 30 degrees, with humidex values in the high 30s to low 40s.

Meanwhile, overnight lows near 20 degrees are also expected through this period, providing little relief from the heat.

A slightly cooler air mass is expected to move into the area this weekend, however, there is considerable uncertainty.

Environment Canada notes that hot and humid air can also bring deteriorating air quality and can result in the Air Quality Health Index approaching the high-risk category.

The risks are greater for young children, pregnant women, older adults, people with chronic illnesses and people working or exercising outdoors.

You should make sure to check on these individuals and see that they are cool and drinking water.

If you’re outside for any reason, you are encouraged to shade yourself with an umbrella or a wide-brimmed hat and never leave people or pets inside a parked vehicle, as temperatures can rise to dangerous levels.

You can also keep your house cool and block the sun by closing curtains or blinds.

For more weather updates – visit Environment Canada’s website