SALEM, Ore. (AP) — Hundreds of deaths in Canada, Oregon and Washington may have been caused by the historic heat wave that baked the Pacific Northwest and shattered all-time temperature records in usually temperate cities.

Oregon health officials said late Wednesday more than 60 deaths have been tied to the heat, with the state's largest county, Multnomah, blaming the weather for 45 deaths since the heat wave began Friday.

British Columbia’s chief coroner, Lisa Lapointe, said her office received reports of at least 486 “sudden and unexpected deaths” between Friday and 1 p.m. Wednesday. Normally, she said about 165 people would die in the province over a five-day period.

“While it is too early to say with certainty how many of these deaths are heat related, it is believed likely that the significant increase in deaths reported is attributable to the extreme weather,” LaPointe said in a statement.

Like Seattle, many homes in Vancouver, British Columbia, don’t have air conditioning.

“Vancouver has never experienced heat like this, and sadly dozens of people are dying because of it,” Vancouver police Sgt. Steve Addison said in a statement.

Washington state authorities had linked more than 20 deaths to the heat, but that number was likely to rise.

The heat wave was caused by what meteorologists described as a dome of high pressure over the Northwest and worsened by human-caused climate change, which is making such extreme weather events more likely and more intense. Seattle, Portland and many other cities broke all-time heat records, with temperatures in some places reaching above 115 degrees Fahrenheit (46 Celsius).

While the temperatures had cooled considerably in western Washington, Oregon and British Columbia by Wednesday, interior regions were still sweating through triple-digit temperatures as the weather system moved east into the intermountain West and the Plains.

Environment Canada issued heat warnings Wednesday for southern Alberta and Saskatchewan. Heat warnings also were in place for parts of Washington, Oregon, Idaho and Montana.

In Alberta, “a prolonged, dangerous, and historic heat wave will persist through this week,” Environment Canada said.

The very high temperatures or humidity conditions posed an elevated risk of heatstroke or heat exhaustion.

In a statement, Oregon’s Multnomah County medical examiner blamed 45 heat deaths there on hyperthermia, an abnormally high body temperature caused by a failure of the body to deal with heat. The victims ranged in age from 44 to 97.

The county that includes Portland said that between 2017 and 2019, there were only 12 hyperthermia deaths in all of Oregon.

“This was a true health crisis that has underscored how deadly an extreme heat wave can be, especially to otherwise vulnerable people,’’ Dr. Jennifer Vines, the county's health officer, said in a statement.

The King County medical examiner's office, which covers an area including Seattle, said at least 13 people died due to the heat. The victims were between 61 and 97 years of age.

In eastern Washington, the Spokane Fire Department found two people dead in an apartment building Wednesday who had been suffering symptoms of heat-related stress, TV station KREM reported.

The heat led a power company in Spokane to impose rolling blackouts because of the strain on the electrical grid. Avista Utilities says it's trying to limit outages to one hour per customer.

Renee Swecker, 66, of Clayton, Washington, visited a splashpad fountain in downtown Spokane’s Riverfront Park with her grandchildren Wednesday, saying they “are going everywhere where there is water.”

“I’m praying for rain every day,” Swecker said.