Many parts of southern Ontario, including Toronto, remain under a heat warning issued by Environment Canada on Saturday.
Cooler temperatures are expected later this week when the humidity dissipates.
Environment Canada also expects humidex values to make it feel like closer to 40 C outside.
According to Environment Canada, risks associated with the heat wave "are greater for young children, pregnant women, older adults, people with chronic illnesses and people working or exercising outdoors".
Island Health has also issued its own public service announcement on the hot temperatures, reinforcing Environment Canada's message to check on those who may be vulnerable.
Some effects to watch for include swelling, cramps, rash, fainting, heat exhaustion, heat stroke and the worsening of some health conditions. "The severe weather threat will diminish this evening", the national weather agency said in its advisory Monday morning.
You are advised to drink plenty of water and stay in a cool place and make sure family and friends are doing the same, and never leave people or pets in a parked auto. A section of eastern Vancouver Island from Cedar to Duncan was already under the extreme rating, which is the highest possible fire danger rating.
There are no campfire bans yet in place anywhere in B.C., but large open fires are banned in the Kamloops, Southeast and Cariboo fire centres.