Millions of people in western Canada and the northwestern United States were under heat alerts Wednesday as the region baked in record-breaking temperatures and police reported scores of deaths likely linked to the scorching conditions.
The heatwave has stretched emergency services, with at least 134 people dying suddenly since Friday in the Vancouver area, according to Canadian police.
In the northwest US city of Seattle, doctors reported a flood of heatstroke victims, and at least two patients -- aged 65 and 68 -- died of hyperthermia as their bodies overheated, according to the Seattle Times.
Soaring temperatures in California's valley, mountain and desert areas raised fears of wildfires amid windy dry conditions.
The US National Weather Service warned of "a possibility of dry lightning strikes... creating the potential for lightning-sparked fires."
President Joe Biden was due to host a virtual meeting with governors from western states to discuss the threat of wildfires spurred on by the heat wave.
Federal officials say the fire season is already outpacing last year's -- the worst on record in California.
On Tuesday, the Vancouver Police Department alone said it had responded to more than 65 sudden deaths since Friday, with the vast majority "related to the heat."
Canada set a new all-time high-temperature record for a third day in a row Tuesday, reaching 121 degrees Fahrenheit (49.5 degrees Celsius) in Lytton, British Columbia, about 155 miles (250 kilometers) east of Vancouver, the country's weather service, Environment Canada, reported.
Some Vancouver locals said they had never experienced such temperatures before.
"It's never this bad. I've never seen anything like this," said resident who only gave her name as Rosa.
"I hope it never becomes like this ever again. This is too much."
Others lamented that some residents were more vulnerable to the heat than others.
"I feel for those people whether they're the elderly demographic or people who live on the downtown eastside of Vancouver who don't have a cool spot to live or sleep," said river swimmer Graham Griedger.
Climate change is causing record-setting temperatures to become more frequent. Globally, the decade to 2019 was the hottest recorded, and the five hottest years have all occurred within the last five years.
The scorching heat stretching to Canada's Arctic territories has been blamed on a high-pressure "heat dome" trapping warm air in the region.
Temperatures in the US Pacific Northwest cities of Portland and Seattle reached levels not seen since record-keeping began in the 1940s: 115 degrees Fahrenheit in Portland and 108 in Seattle Monday.
Vancouver on the Pacific coast has for several days recorded temperatures above 86 degrees Fahrenheit -- almost 20 degrees above seasonal norms.
The chief coroner for British Columbia, which includes Vancouver, said the province had "experienced a significant increase in deaths reported where it is suspected that extreme heat has been contributory."
The service said in a statement it recorded 233 deaths between Friday and Monday, compared with 130 on average.
"We are in the midst of the hottest week British Columbians have ever experienced, and there are consequences to that, disastrous consequences for families and for communities," British Columbia Premier John Horgan told a news conference.
He urged "checking up on those people we know might be at risk, making sure we have cold compresses in the fridge or we're staying in the coolest part of our homes, and making sure that we're taking steps to get through this heat wave."
Environment Canada said the "prolonged, dangerous and historic heat wave will persist through this week."
The heat wave has forced schools and Covid-19 vaccination centers to close in the Vancouver area, while officials set up temporary water fountains and misting stations on street corners.
Cities across the western United States and Canada opened emergency cooling centers and outreach workers handed out bottles of water and hats.