Environment Canada has issued a heat warning for much of B.C. for Monday, including Kelowna and Penticton.
Heat warnings are issued in Newfoundland and Labrador when temperatures are expected to reach 26 degrees or higher-or 34 with humidex-for two or more days in a row.
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".
The weather office says the inner south coast - including eastern Vancouver Island, the Sunshine Coast, Howe Sound, the southern Gulf Islands, Victoria and Vancouver - will see temperatures climb to at least 28 C, although conditions should be cooler close to the water.
Some effects to watch for include swelling, cramps, rash, fainting, heat exhaustion, heat stroke and the worsening of some health conditions.
Peel Public Health also has suggestions on its website.
The severe weather came amid a bout of hot summer temperatures.
It suggests drinking plenty of water-even if you don't feel thirsty-and keeping to cool areas.
The BC Wildfire Service raised the fire danger rating for the Lake Cowichan area to "extreme" on Monday.
The Lake Cowichan Fire Department posted about the upgraded danger rating to Facebook and reminded campers to make sure campfires are fully extinguished.