Even 90-Degree Heat Could Be Devastating
The Pacific Northwest’s early heat wave is a warning for the world.
This story was originally published in High Country News.
As 90-degree temperatures bore down on the Pacific Northwest in May, real-time reporting to the CDC showed that heat-related emergency-room-visit rates were more than 30 times higher than they had been the previous weekend. Though state officials caution that the data are preliminary, Oregon and Washington confirmed 160 heat-related ER visits from May 12 to 15. In Washington, the average number of visits during a similar period is about seven. At least 10 people in that state were hospitalized. And heat-related emergencies may have been just one public-health impact of the four days of record temperatures: Heat waves are linked to increased aggression, poor school performance, and worse health overall.
That temperatures in western Oregon and Washington hit the low-to-mid 90s is not in itself remarkable. But the timing of the heat wave was. This time of year, “our bodies aren’t acclimated to those temperatures,” says Adelle Monteblanco, a public-health professor at Pacific University, near Portland, who researches extreme heat. This makes even moderately high heat more dangerous: Health risks increase when temperatures are higher than locals are used to, not just when they reach triple digits. Some communities faced temperatures nearly 30 degrees higher than is normal for mid-May.
In May, people’s behavior has not yet adapted to warmer temperatures, Monteblanco says: After a long, dark winter, “I think people probably took risks they shouldn’t have.” “They probably weren’t drinking enough water,” she says. “They ran their errands during the hottest part of the day. They didn’t wear the right clothing, and they didn’t pace themselves.”
Heat is the top weather-related killer in the U.S., but its effects remain underestimated even as temperatures rise: Earlier, longer, and hotter heat waves are an expected result of climate change. “We often talk about it as a silent killer,” Monteblanco says. “We can’t see it. It’s slow-moving. But if you are unhoused or an outdoor worker, it doesn’t look so invisible anymore.” Members of those groups are also at higher risk from earlier heat.
In addition to direct health effects, research has linked heat waves to increases in gun violence, as well as domestic and other violence. “Think about how testy you get when you get hot,” says Ann Loeffler, a public-health official in Multnomah County, which includes Portland. Although a direct connection is hard to draw, the CDC says heat exposure can also contribute to overdose deaths. Drowning is another known impact of high heat.
Monteblanco, whose research focuses on pregnant people and children, is also concerned about longer-term effects: Prolonged heat is linked to preterm births, lower birth weights, and gestational diabetes. “Heat waves are going to exacerbate our maternal-health crisis,” she says, referring to recent and significant increases in maternal deaths, especially among people of color.
Loeffler says her office did everything it could to protect residents, distributing water and sunscreen to unhoused people and helping residents find air-conditioned libraries and malls. But facilities that are normally open in the summer were not available: Many water features hadn’t opened yet, nearly a third of the city’s libraries are closed this year for construction, and county officials decided not to open additional cooling centers, citing easier post-pandemic access to other public spaces.
“We have to prepare our cities for hotter temperatures,” Monteblanco says, surprised that some cities didn’t do more. “Cooling centers are central to preparation, response, and resilience.” But interventions to help people protect themselves also don’t go far enough, she observes: “At this stage, I’m just so eager to vote for policy changes.” She says useful steps include the newly passed Pregnant Workers Fairness Act, which advocates expect will help protect pregnant workers from heat, and the recently reintroduced Black Maternal Health Momnibus Act, along with anything that reduces dependence on fossil fuels.
“The risk is only going to continue to grow,” she says.