Environment Canada has issued heat warnings for British Columbia and Alberta
Dozens of people have died in Canada as temperatures across the southern Pacific Northwest continue to smash records.
Police in British Columbia say they have responded to over 60 sudden deaths since Monday, including many seniors.
They said the heatwave baking the region was a contributing factor to the fatalities.
Temperatures in Lytton, British Columbia, soared to 47.9C (118.2F) on Monday, up from 46.6C (116F) on Sunday.
Before this week, temperatures in Canada had never passed 45C (113F).
"Check on your neighbours, check on family members, check on seniors you may know," said Royal Canadian Mounted Police Cpl Mike Kalanj, based in the Vancouver suburb of Burnaby.
"We are seeing this weather can be deadly for vulnerable members of our community, especially the elderly and those with underlying health issues. It is imperative we check on one another during this extreme heat."
In Burnaby alone, police say they have responded to 25 cases of "sudden death", adding that many of them were pensioners.
Paramedics in British Columbia responded to 107 heat exhaustion calls and 32 heatstroke calls on Sunday, the Globe & Mail reported.
In the tiny village of Lytton, resident Meghan Fandrich told the Globe & Mail it had been "almost impossible" to go outside.
"It has been intolerable," she said, adding that she sent her young daughter to stay with family elsewhere in British Columbia where temperatures are marginally cooler.
"We're trying to stay indoors as much as possible. I mean, we are used to the heat, and it is a dry heat, but 30 [degrees] is a lot different from 47."
Environment Canada has issued heat warnings for the provinces of British Columbia and Alberta, along with areas of Saskatchewan, the Northwest Territories and a section of Yukon.
"We are the second coldest country in the world and the snowiest," said David Phillips, a senior climatologist for Environment Canada.
"We often see cold snaps and blizzards but not often do we talk about hot weather like this," he said. "Dubai would be cooler than what we're seeing now."
How has the heatwave affected the US?
Temperatures in the American cities of Portland and Seattle have reached the highest levels since record-keeping began in the 1940s.
Portland in Oregon hit 46.1C (115F) and Seattle 42.2C (108F), according to the US National Weather Service. The heat is intense enough to melt cables, shutting down the Portland Streetcar Service on Sunday.
An electrical utility in Spokane, Washington, has introduced rolling blackouts to cope with huge power demand as residents run air conditioners.
One Seattle resident told the AFP news agency that the city in Washington state felt like a desert.
"Normally it's probably like, maybe 60, 70 degrees is a great day - everybody is outside in shorts and T-shirts - but this is... ridiculous," the resident said.
Amazon allowed members of the public into areas of its Seattle headquarters as a cooling-off location on Monday, while residents in Portland also flocked to cooling centres.
Experts say that climate change is expected to increase the frequency of extreme weather events, such as heatwaves. However, linking any single event to global warming is complicated.