A Salvation Army EMS vehicle is setup as a cooling station as people lineup to get into a splash park while trying to beat the heat in Calgary, Alberta, Wednesday, June 30, 2021. Environment Canada warns the torrid heat wave that has settled over much of Western Canada won't lift for days. Credit: Jeff McIntosh/The Canadian Press via AP

Many of the dead were found alone, in homes without air conditioning or fans. Some were elderly—one as old as 97. The body of an immigrant farm laborer was found in an Oregon nursery.

As forecasters warned of a record-breaking heat wave in the Pacific Northwest and western Canada last weekend, officials set up cooling centers, distributed water to the homeless and took other steps. Still, hundreds of people are believed to have died from Friday to Tuesday.

An excessive heat warning remained in effect for parts of the interior Northwest and western Canada Thursday.

The death toll in Oregon alone reached 79, the Oregon state medical examiner said Thursday, with most occurring in Multnomah County, which encompasses Portland.

In Canada, British Columbia's chief coroner, Lisa Lapointe, said her office received reports of at least 486 "sudden and unexpected deaths" between Friday and Wednesday afternoon. Normally, she said about 165 people would die in the province over a five-day period.

She said it was too soon to say with certainty how many deaths were heat related, but that it was likely the heat was behind most of them.

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

Salem Fire Department paramedics and employees of Falck Northwest ambulances respond to a heat exposure call during a heat wave, Saturday, June 26, 2021, in Salem, Ore. Credit: AP Photo/Nathan Howard

In Oregon's Multnomah County, the average victim's age was 67 and the oldest was 97, according to county Health Officer Jennifer Vines.

In a telephone interview Thursday, Vines said she had been worried about fatalities amid the weather forecasts. Authorities tried to prepare as best they could, turning nine air-conditioned county libraries into cooling centers.

Between Friday and Monday, 7,600 people cooled off amid the stacks of books. Others went to three more cooling centers. Nearly 60 teams sought out homeless people, offering water and electrolytes.

"We scoured the county with , with calls to building managers of low-income housing to be checking on their residents," Vines said.

But the efforts weren't enough, she said: "It's been really sobering to see these initial (fatality) numbers come out."

Field laborers work at Ernst Nursery & Farms, the location of a heat death during last weekend's record breaking temperatures on Thursday, July, 1, 2021, in St. Paul, Ore. Oregon OSHA is investigating Ernst Nursery and Farms, which did not respond to a request for comment. Reyna Lopez, executive director of a northwest farmworkers' union, known by its Spanish-language initials, PCUN, called the death "shameful" and faulted both Oregon OSHA for not adopting emergency rules ahead of the heat wave, and the nursery. Credit: AP Photo/Nathan Howard

Oregon Office of Emergency Management Director Andrew Phelps agreed. "Learning of the tragic loss of life as a result of the recent heat wave is heartbreaking. As an emergency manager – and Oregonian – it is devastating that people were unable to access the help they needed during an emergency," he said.

Among the dead was a farm laborer who collapsed Saturday and was found by fellow workers at a nursery in rural St. Paul, Oregon. The workers had been moving irrigation lines, said Aaron Corvin, spokesman for the state's worker safety agency, Oregon Occupational Safety and Health, or Oregon OSHA.

Oregon OSHA, whose database listed the death as heat-related, is investigating labor contractor Andres Pablo Lucas and Ernst Nursery and Farms, which did not respond to a request for comment. Pablo Lucas declined to comment Thursday.

This satellite image provided by European Union, Copernicus Sentinel-2 data (processed by Spacetec) shows a wildfire burning 40 km (about 25 miles) northeast of Pink Mountain in British Columbia. Credit: European Union, Copernicus Sentinel-2 data via AP

Farm worker Pedro Lucas said the man who died was his uncle, Sebastian Francisco Perez, from Ixcan, Guatemala. He had turned 38 the day before he died.

Lucas, who is cousins with the labor contractor, was summoned to the scene. But by the time he arrived, his uncle was unconscious and dying. An ambulance crew tried to revive him but failed. Lucas said Perez was used to working in the heat and that the family is awaiting an autopsy report.

Reyna Lopez, executive director of a northwest farmworkers' union, known by its Spanish-language initials, PCUN, called the death "shameful" and faulted both Oregon OSHA for not adopting emergency rules ahead of the heat wave, and the nursery.

Corvin said Oregon OSHA is "exploring adopting emergency requirements, and we continue to engage in discussions with labor and employer stakeholders."

Gregory Matarazzo takes a break from cycling as the temperatures hovered over 100 degrees in Missoula, Montana, on Wednesday, June 30, 2021. Credit: AP Photo/Tommy Martino

He added that employers are obligated to provide ample water, shade, additional breaks and training about heat hazards.

An executive order issued in March 2020 by Oregon Gov. Kate Brown would formalize protecting workers from heat, but it is coming too late for the dead farmworker. Brown's order focuses on reducing greenhouse gas emissions and also tells the Oregon Health Authority and Oregon OSHA to jointly propose standards to protect workers from excessive heat and wildfire smoke.

They had until June 30 to submit the proposals, but due to the coronavirus pandemic, the two agencies requested the deadline be pushed back to September.

In Bend, Oregon, a scenic town next to the snowy Cascade Range, the bodies of two men were found Sunday on a road where dozens of stay in trailers and tents.

In this photo provided by Marshall Potts Music, the Sparks Lake wildfire burns in Kamloops, British Columbia, on Wednesday, June 30, 2021. Credit: Courtesy of Marshall Potts Music via The Canadian Press via AP

Volunteer Luke Richter said he stepped into the trailer where one of the men, Alonzo "Lonnie" Boardman, was found.

"It was very obviously too late. It was basically a microwave in there," Richter told Oregon Public Broadcasting.

Cooling stations had been set up at the campsite on Saturday, with water, sports drinks and ice available.

Weather experts say the number of heat waves are only likely to rise in the Pacific Northwest, a region normally known for cool, rainy weather, with a few hot, sunny days mixed in, and where many people don't have air conditioning.

"I think the community has to be realistic that we are going to be having this as a more usual occurrence and not a one-off, and that we need to be preparing as a community," said Dr. Steven Mitchell of Seattle's Harborview Medical Center, which treated an unprecedented number of severe heat-related cases. "We need to be really augmenting our disaster response."

  • In this photo provided by Marshall Potts Music, the Sparks Lake wildfire burns in Kamloops, British Columbia, on Wednesday, June 30, 2021. Credit: Courtesy of Marshall Potts Music via The Canadian Press via AP

  • Jenny Rol, right, holds her 14-month-old daughter Safi in a water feature to cool off at a park in Missoula, Montana, as temperatures approached 100 degrees on Wednesday, June 30, 2021. A heat wave has gripped the Pacific Northwest and is moving east. Credit: AP Photo/Tommy Martino

  • Salem Fire Department paramedics and employees of Falck Northwest ambulance service respond to a heat exposure call during a heat wave, Saturday, June 26, 2021, in Salem, Ore. Credit: AP Photo/Nathan Howard

  • Salem Fire Department paramedic Justin Jones tries to stay cool after responding to a heat exposure call during a heat wave, Saturday, June 26, 2021, in Salem, Ore. Credit: AP Photo/Nathan Howard

  • Jeff Krupczak and daughter Savanna, 12, cool off in the Clark Fork River in Missoula, Montana, on Wednesday, June 30, 2021. Credit: AP Photo/Tommy Martino

  • A group of kayakers shares space with a pair of ducks near the Hiram M. Chittenden Ballard Locks, Wednesday, June 30, 2021, under sunny skies in Seattle. Temperatures cooled considerably in western Washington, Oregon and British Columbia Wednesday after several days of record-breaking heat, but the interior regions of the region were still sweating through triple-digit temperatures as the weather system moved east. The Locks connect Lake Union and Salmon Bay with Puget Sound. Credit: AP Photo/Ted S. Warren

  • A person uses an umbrella for shade from the sun while walking near Pike Place Market, Tuesday, June 29, 2021, in Seattle. The unprecedented Northwest U.S. heat wave that slammed Seattle and Portland, Oregon, moved inland Tuesday—prompting an electrical utility in Spokane, Washington, to resume rolling blackouts amid heavy power demand. Credit: AP Photo/Ted S. Warren

  • In this aerial photo taken from a helicopter, a wildfire burns in the mountains north of Lytton, British Columbia, on Thursday, July 1, 2021. A wildfire that forced people to flee a small town in British Columbia that had set record high temperatures for Canada on three consecutive days burned out of control Thursday as relatives desperately sought information on evacuees. Credit: Darryl Dyck/The Canadian Press via AP

  • In this aerial photo taken from a helicopter, a wildfire burns in the mountains north of Lytton, British Columbia, on Thursday, July 1, 2021. A wildfire that forced people to flee a small town in British Columbia that had set record high temperatures for Canada on three consecutive days burned out of control Thursday as relatives desperately sought information on evacuees. Credit: Darryl Dyck/The Canadian Press via AP

This week's 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 records, with temperatures in some places reaching above 115 degrees Fahrenheit (46 Celsius).