Villagers in an area engulfed by wild fires have been forced to flee their homes.
Authorities in British Columbia recorded at least 486 “sudden and unexpected” deaths between Saturday and Wednesday.
Another 60 fatalities in the US state of Oregon have been linked to the heat.
The village of Lytton, which on Tuesday recorded a new Canadian high of 121.2 F (49.6 C), was evacuated the next day as a blaze took hold.
David Phillips, senior climatologist at Environment and Climate Change Canada, a government agency, said climate change looked to be a factor causing a heat dome, a weather phenomenon that traps heat, blocking other weather systems from moving in.
As well as the deaths, people’s belongings have been melted or damaged, as people in Canada, Oregon and Washington state have shown.
In the city of Portland in Oregon, the siding of a house started to peel off in the heat.
Some people complained their shoes had shrunk.
Squirrels were seen lying flat out to try to disperse the heat.
In Seattle, coconut oil melted in the tub.
Householders have rigged up air-conditioning units.
Candles didn’t need flames for the wax to melt.