PORTLAND, Ore. — Mandi Luke’s symptoms came on slowly: spots on her vision, fuzziness in her brain. Hunkered down in her tent beside a bike path in Portland’s Lents neighborhood, she sipped Gatorade and made sure a breeze flowed through an opening in the fabric.

Her husband — a former Army medic — was helping treat sick people at another camp. When he texted to check on her, she tried to reassure him. Luke, 36, had been on and off the streets for years. She knew the dangers of heat, knew how to look after herself. And she knew that abandoning her home, her dog and her life’s possessions to seek out air conditioning was not an option.

But this was so much worse than the heat waves she’d seen before. Portland had notched record highs the past two days, and now the city was on track to hit 116 degrees.

The air inside the tent was still and stifling. Luke became woozy. Her pulse stuttered. It seemed like she couldn’t get enough oxygen to her lungs.

She was gripped by a terrifying thought: This could kill her.

In an era of escalating climate change, extreme heat is the United States’ most fatal form of weather disaster. Already this summer, hundreds of Americans have lost their lives amid a series of record-setting heat waves that scientists say would not have happened if not for human-caused warming. Even now, a fourth dome of punishing heat is poised to roast the Intermountain West.

The onslaught of heat in places that rarely see such high temperatures has pushed communities to the breaking point. Roads have buckled, and train cables have melted. Emergency departments were overwhelmed.

Yet as officials assess the staggering toll of recent heat waves — at least 115 deaths in Oregon — they are realizing their social infrastructure is equally in need of repair. Long-standing inequities in housing and health care put the region’s poorest residents at greatest risk. Official warnings and government services didn’t reach those who most needed the help. Almost every victim of the heat wave died alone.

“The deepest challenge is the intersection of the ecological crisis and the social justice crisis,” said sociologist Eric Klinenberg, an expert on climate disasters. “If we’re not responsible for one another, that’s a recipe for mass fatalities.”

Homeless in a heat island

When Luke stopped responding to texts, Kristle Delihanty began to worry.

Delihanty, the 41-year-old founder of local nonprofit PDX Saints, had met Luke while delivering food and supplies to tent encampments during the pandemic. The two had bonded over their shared fashion sense and past struggles: drug use, arrests, homelessness. When the city swept Luke and her husband from their previous camp by a highway overpass this spring, Delihanty helped them move their belongings to their new spot by the bike path.

Now, unable to leave her post running a cooling station in nearby Lents Park, Delihanty sent another volunteer to check on her friend.

The van returned soon after, she ran to slide the door open, “and I heard her just wailing,” Delihanty recalled.

Luke’s skin was clammy, her limbs too weak for her to move on her own. Delihanty heaved the sick woman into an air-conditioned jeep and covered her with ice packs and cool, wet cloths.

These were the symptoms of heat exhaustion — a sign that Luke’s body was struggling to regulate her internal temperature after three straight days of scorching conditions. Severe dehydration had dramatically lowered her blood pressure, making her dizzy and confused. Heavy breathing and a rapid pulse were evidence of organs under stress.

Heat illness can be life-threatening if untreated, said David Markel, an emergency physician at Swedish Medical Center-Cherry Hill in Seattle who treated about a dozen patients during the Northwest heat wave. As a person’s body temperature starts to rise, their kidneys and liver stop functioning. The brain swells, the central nervous system starts to break down. Victims may become delirious, have seizures or fall into a coma. This cascade of organ failure is behind the hundreds of heat deaths already recorded this summer.

“Human bodies are really resilient,” said Kristie Ebi, an epidemiologist at the Center for Health and the Global Environment at the University of Washington. “But there are thresholds for what we can withstand.”

Of all the people suffering during the Northwest heat wave, Luke was among the most vulnerable. She has epilepsy and heart problems, and she suffers from mental illnesses made worse by extreme temperatures. But homelessness and joblessness meant her conditions often went untreated.

Luke’s neighborhood in southeast Portland is also one of the city’s worst urban heat islands. Huge expanses of asphalt absorb and amplify the sun’s radiation, with few trees to offer relief. Tall buildings create caverns that trap heat. Exhaust from traffic on Interstate 205 exacerbates the problem.

Driving around the city on June 28, the worst day of the heat dome, Portland State University professor Vivek Shandas measured an air temperature of 124 degrees Fahrenheit — a full 25 degrees higher than the wealthier, leafier parts of the city. The pavement was a blistering 180 degrees, hot enough to give third-degree burns.

A Washington Post analysis of preliminary mortality data released last week showed that 61 percent of confirmed deaths in Multnomah County occurred in Zip codes with poverty rates higher than the country average. Luke’s Zip code, the second poorest in the county, was among the hardest hit.

At least two of the county’s 54 confirmed deaths were people experiencing homelessness, according to Multnomah officials. At least four others lived in public housing. None of the victims had central air conditioning in their homes.

A decades-old body of research has established that extreme heat hits low-income neighborhoods and communities of color the hardest. They are disproportionately likely to live in buildings with poor ventilation and surfaces that trap heat. Even those who have air conditioning may be reluctant to use it for fear of a skyrocketing electric bill. People who are elderly and those who have chronic health conditions are most at risk — especially if those conditions are exacerbated by an inability to access treatment.

This pattern of deaths was predictable, Ebi said. “But the number one message I always have is, almost all these deaths are also preventable."

A need for new plans

State officials knew extreme heat was coming. Average temperatures in Oregon have increased about 2 degrees Fahrenheit since 1900, and the state is projected to warm by as much as 9 degrees by the end of this century. Last year, Oregon for the first time added extreme heat to the list of possible disasters addressed in its “natural hazard mitigation plan.”

But climate change has outstripped the pace of public policy. When the heat dome scorched the state last month, Oregon did not have a heat early warning and response system, the gold standard for disaster planning. Residents in the typically temperate region didn’t know how to cope with extreme temperatures. A proposed rule to protect outdoor workers from wildfire smoke and heat had not yet been adopted.

In Multnomah County, officials sent out a salvo of forecasts and safety tips in five languages. Residents were urged to seek relief at libraries or one of three 24-hour cooling centers. An army of county employees and volunteers distributed thousands of water bottles. Public transit was made free for anyone who needed it.

Yet the response was hampered by officials’ inability to effectively reach residents — and residents’ inability to take advantage of the help that was offered. Calls to 211 went unanswered because the nonprofit that runs the phone line was not fully staffed over the weekend, officials said. The county’s light rail had to suspend service when one of its power cables melted. The number of people arriving at cooling centers was far below the buildings’ capacities, even as Portland broke its previous heat record by 9 degrees Fahrenheit.

“The heartbreaking thing about this heat wave is, there were resources that were available to communities … but folks couldn’t access those resources to protect themselves,” Andrew Phelps, director of the Oregon Office of Emergency Management, told reporters last week.

Yet the resources offered weren’t necessarily what residents needed, said Klinenberg, the sociologist. Most people do not want to leave their homes during a heat disaster, he explained, because home is where they feel safest — whether or not it is actually a safe place to be. Nearby mobile cooling stations, such as air-conditioned trailers and portable misters, are far more appealing than a centralized cooling center several neighborhoods away.

And telling people to seek help if they feel sick isn’t helpful, Klinenberg added, because the confusion caused by heat exhaustion means that many people don’t realize they’re in danger.

“They need someone to check on them,” he said. “That’s why people who are socially isolated are so much more likely to die.”

The most effective strategy for preventing heat deaths is direct outreach, experts say. After a brutal nine-day heat wave killed 118 people in Philadelphia in 1993, the city implemented one of the nation’s most robust heat response programs. Now, when the mercury spikes, an alert goes out through Philly’s mass notification system. The number for a 24-hour hotline staffed by nurses flashes from one of the city’s tallest high rises. Some 5,000 volunteer “block captains” are mobilized to check on high-risk neighbors, and field teams of health experts follow up with anyone who is ill.

A study by a team of Boston researchers found that the Philadelphia system averted an average of 45 deaths per year.

“It’s not something you pull together overnight or even in a few days,” Ebi said. “You can’t really blame the city, the county and the state services [for recent deaths in Oregon] because they didn’t have this.”

But this year’s heat wave should be a warning to Oregon, the Northwest and the rest of the country, she said. Climate change is bringing unthinkable highs to places that have never been so hot. It is raising overnight temperatures, denying residents the relief that usually comes after dark. It is prolonging extreme events, straining electric utilities and human bodies.

“No place can afford not to have one of these plans,” Ebi said. “Everywhere is getting hotter. All of us are at risk.”

‘The community should have done better’

For a while, it seemed like Luke would be okay. She felt well enough to drink water and sit at some shaded picnic tables, where PDX Saints volunteers could keep an eye on her.

Meanwhile, Delihanty made another call to the city commissioner’s office. For three days, she’d been asking them to turn on the sprinkler at a nearby amateur baseball stadium. “Give us 30 minutes,” they kept telling her. But every 30 minutes, the mercury rose another degree.

Just when officials gave Delihanty the go-ahead, Luke started to turn red. She heaved as if to vomit, but only foam came out. Her skin was dry and hot to the touch — she wasn’t able to sweat.

Luke was experiencing heat stroke. Her internal temperature was climbing, and her organs were at risk of breaking down.

Delihanty loaded her friend back into the Jeep and rushed to the stadium. There, she pulled Luke onto her back and carried her to the sprinkler. “I’m sorry,” Luke was crying. “I’m sorry I waited so long. I didn’t want to leave my tent, my dog, everything I owned.”

“It’s okay,” Delihanty told her. “None of that matters.” She continued to hold Luke as the cool water cascaded over both of them. “I love you, it’s okay.”

It wasn’t until that evening, in the driveway of her air-conditioned home, that Delihanty was able to process what had happened. Luke had risked death because she couldn’t afford to lose the few belongings she had. Delihanty put her head in her hands and wept.

“There is nothing worth her life, but humanity has not proven that,” she said. “It’s the community that should have done better. Not her.”

This question — how can the community be better? — preoccupies climate experts at the Oregon Health Authority.

“People really mobilized” during the heat wave, said Gabriela Goldfarb, manager of the OHA’s environmental public health section. “But it wasn’t enough. And the information we’re finding is that it’s our social system … that needs to change.”

Preventing deaths during climate disasters is not just about emergency response, she continued. It’s about building “social resilience,” addressing the isolation and inequality that make people vulnerable in the first place.

That means reducing urban heat islands like the one in Luke’s neighborhood. It means expanding access to health care so the medical conditions that put people at risk of heat illness don’t go untreated. It means more funding for organizations with close ties to marginalized groups that will be better able to reach people who are elderly, homeless or nonnative English speakers when a crisis is heading their way.

Emily York, who is overseeing an update of Oregon’s 2017 Climate and Health Resilience Plan, said efforts like this are underway. The state legislature recently approved new funds for local public health agencies to develop climate change and environmental hazard programs. The OHA is collaborating with community groups to develop practical, easy-to-understand infographics about surviving heat, smoke, flooding and other climate impacts. The agency has mapped out areas of high “social vulnerability” to help focus its adaptation plans.

“Our marching orders throughout our agency are to eliminate health inequities by 2030,” Goldfarb said.

And in the short term, she added, “Look out for your neighbor. I think that’s what we saw that worked.”

Swept

Two weeks after the heat wave, Luke’s weakness has subsided. But the trauma stays with her. She runs through the day over and over in her head, asking how things could have gone differently. What if the city had provided portable swamp coolers to people in tents? What if they handed out informational materials to help people recognize signs they were getting sick? Why hadn’t any of the hundreds of city workers who deployed that weekend simply asked homeless folks what they needed?

“If it hadn’t been for Kristle, I probably would have died.” Suddenly, her eyes filled with tears. “I wish the city cared,” she sobbed. “I wish there was some way they could learn what it’s like to be out here.”

She walked back to the tent along the bike path, where her husband, Angel, was waiting with bad news. Rangers from the Portland Department of Parks and Recreation were doing another sweep. The couple had 48 hours to move.

“They’re labeling it health and safety issues,” her husband said.

“Oh god,” Luke rolled her eyes. What about their health and safety? Moving might mean losing the community they’d made with other people living along the bike path. It might mean ending up somewhere more dangerous and exposed.

Then she shook her head and braced herself for the inevitable. She would start over. And she would try to be ready for the next crisis to come.