As the mercury is set to soar into the mid-30s, Environment Canada has issued a Heat Warning for the region.

The weather agency says maximum temperatures on Sunday are expected to reach between 32 and 34 degrees Celsius.

Continued heat is expected on Monday but maximum temperatures have the potential to be slightly cooler and reach between 29 and 32 degrees Celsius in some places.

Little relief from the heat during the overnight hours of Sunday night into early Monday morning is expected with minimum temperatures forecast to drop to between 21 and 24 degrees Celsius.

Humidex values on Sunday and Monday are expected to reach between 36 and 42.

This heat event has the potential to continue into Tuesday for some areas.

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.

Watch for the effects of heat illness: swelling, rash, cramps, fainting, heat exhaustion, heat stroke, and the worsening of some health conditions.

Drink plenty of water even before you feel thirsty and stay in a cool place.

Never leave people or pets inside a parked vehicle.

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.