PORTLAND, Ore. ­— Kim and Kathy Stoughton thought they could wait out the record-breaking heat in their east Portland apartment, even though they don't have air conditioning.

But by Sunday, they couldn’t take it anymore.

“I felt fatigued, extremely uncomfortable, mad,” said Kim, who is in his 60s.

He was also dizzy and confused, signs of heatstroke. So the couple headed to Sunrise Center, a community-center-turned-cooling-station open 24 hours through Tuesday.

Thousands around the city are grappling with a similar choices as the city grinds through a third day of record-breaking heat. Unfolding against the backdrop of human-caused climate change, which has raised average temperatures in the Northwest by about 2 degrees Fahrenheit, the extraordinary heat wave set more than a dozen all-time records over the weekend: 112 degrees Fahrenheit in Portland, 115 in The Dalles, a small city on the Columbia River, 104 in Seattle — which had never before seen three days in a row over 100 degrees.

But many of those records had to be promptly revised Monday as the sprawling high-pressure system at the center of the heat wave intensified.

By midafternoon the mercury spiked to 116 in Portland, 108 in Seattle and 117 in Salem, Ore.

In an indication of the heat wave’s exceptional nature, the temperature in Oregon’s capital was the same as the all-time record for Las Vegas.

North of the border, a weather station in Lytton, British Columbia, notched the highest temperature in Canada’s recorded history: 118 degrees Fahrenheit.

Meteorologists estimated that a heat dome of this size and scope is so rare it should be expected only once every several thousand years.

But human-caused warming makes extremes like this more common, scientists say. Unless people drastically reduce greenhouse gas emissions in the coming years, this heat wave doesn’t represent a “new normal” but rather a worrying taste of the effects to come.

A heat wave is pushing temperatures to record highs in the northwestern United States and western Canada. (Christopher Vazquez/The Washington Post)

For now, not even nighttime brings relief. Temperatures linger in the high 90s well after sunset. This is also characteristic of human-caused climate change, which is heating up even faster than days. It also poses some of the greatest risks to human health: hot nights give the body no chance to recover from extreme temperatures, pushing people into heatstroke.

A spokesperson for Seattle and King County Public Health said the agency recorded 41 heat-related visits to emergency departments on Saturday and 91 on Sunday; the county’s previous daily high was nine. Patients were suffered symptoms ranging from vomiting and dizziness to syncope, a temporary loss of consciousness caused by falling blood pressure as people’s bodies are depleted of water.

Between Friday and Sunday, Multnomah County — which includes Portland — recorded 97 emergency department and urgent-care clinic visits for heat illness.

That is an order of magnitude more than the number of visits the county usually sees in a weekend, said spokeswoman Julie Sullivan-Springhetti, and it represents almost half the number of visits the county usually records in an entire summer.

The average number of heat-related emergency visits for a four day period, said spokeswoman Julie Sullivan-Springhetti, is one. She said roughly 1,000 people came to the county’s three main cooling centers Sunday and Monday, and nearly a quarter of the county’s workforce was enlisted in the heat response. Hundreds of people fanned out across the region to distribute water, electrolytes and information to those who were homeless or struggling to stay cool.

Gov. Kate Brown (D) also lifted coronavirus capacity limits on movie theaters, pools and malls to make sure people could congregate in places with air conditioning.

A spokesman for Oregon Health & Science University, the largest hospital in Portland, said the emergency department had seen a small uptick in heat-related illness this weekend.

Meteorologists grasped for adjectives to capture the ferocity and scope of the heat wave: “incredible,” “eye-popping,” “historic,” “insane.”

“As there is no previous occurrence of the event we’re experiencing in the local climatological record, it’s somewhat disconcerting to have no analogy to work with,” the National Weather Service’s Seattle office wrote in an area forecast discussion. “Temperature records will fall in impressive fashion.”

In some cases, pictures were more effective than words.

After canceling its service Sunday, Portland’s streetcar system tweeted an image of a melted and frayed power cable on one of its cars; “Here’s what the heat is doing,” the transit agency said.

Transportation agencies across the region shared photographs of broken and buckled roads — signs of heat so intense it melted asphalt.

At Mount Shasta, not far from the Oregon-California border, a live camera recorded as a lightning-sparked fire swiftly doubled in size amid triple-digit temperatures and perilously low humidity.

And in a photo taken by KOIN news meteorologist Kelley Bayern, Portland’s record temperatures proved just enough to cook an egg on the sidewalk. Perched atop an open-face avocado sandwich, the egg looked good enough to eat. But Bayern abstained.

Sandra Fairbank lives in a tent encampment about 15 minutes from Sunrise Center, near the airport. She has tried to persuade her neighbors to come to Sunrise to cool off, but she’s having trouble.

In May, the mayor approved a measure allowing officials to clear out any areas with eight or more tents.

“People aren’t handling the heat,” Fairbank said. “But they can’t leave their stuff. They’re afraid of it getting taken. It’s terrible.”

Portland’s Joint Offices of Homeless Services have moved thousands of cases of water bottles out to community groups able to drive them to dozens of areas where the more than 14,000 unhoused in Portland live.

According to the city’s communications coordinator Denis Theriault, who visited the distribution center Sunday, they’ve worked with more than 50 organizations to get that water out to the homeless. They employed a similar mass-distribution strategy during last fall’s wildfires, which left the city in a smoky haze for weeks, and when freezing temperatures and ice hit Portland in February.

But this week’s weather is a first-of-its-kind emergency to respond to.

“This is the first time we’ve had this kind of heat and had to open for this,” Theriault said. “Even if things were open all the way,” he says of coronavirus restrictions and closures, “this is one of those heat waves where we would still need to be doing something like this.”

Back at Sunrise Center, the Stoughtons drank lots of water and played Uno to pass the time.

Kim Stoughton grew up in Portland. “In my whole life I have never seen anything like this before. I don’t understand how these homeless people can live in this,” Kim said.

He says he and Kathy will be fine, “as long as we have a roof over our heads.”