The unwelcome arrival of wildfire smoke during a heat wave and in the thick of a resurgent respiratory pandemic created complicated choices Friday for Seattle-area residents, particularly those without access to air conditioning or air filtering, experts said.

“It’s kind of the perfect storm, if you’ll pardon the phrase,” said Graeme Carvlin, an air resources specialist with the Puget Sound Clean Air Agency. “It’s challenging to protect yourself against everything.”

Temperatures cracked 90 degrees Friday and air quality reached unhealthy levels in some parts of the Puget Sound region. Meanwhile, the delta variant of the coronavirus continued its surge, with cases in Washington reaching levels not seen since last fall and winter at the virus’s peak.

Stay inside and secure the windows to keep out the smoke? Draw in outdoor air to beat the heat?

“There’s a clear conflict between what you do when you don’t have access to air conditioning and you have wildfire smoke and high temperatures,” said Kristie Ebi, a professor in the University of Washington Center for Health and the Global Environment. The indoor risk of coronavirus transmission, particularly for those yet to receive the vaccine, adds further complication.

Temperatures Friday weren’t nearly as extreme as they were in late June, when they sent thousands of Washingtonians to the hospital. Nor was the smoke as severe as last September, when Carvlin said it was often two to three times as thick. And King County’s relatively high vaccination rate helps reduce the risk of transmission and severe illness. 


Still, with wildfires, smoke and heat waves forecast to increase in the region because of climate change, health experts and government agencies are increasingly concerned about the intersection of these health risks.

“Those of us worried about climate change have been pretty concerned about this for our region,” Ebi said.

Respiratory threat

Temperatures Friday climbed into the 90s. On Thursday, it reached 95 degrees at Seattle-Tacoma International Airport, just one degree short of the Aug. 12 record, said Steve Reedy, meteorologist for the National Weather Service’s Seattle office.

Smoke from wildfires in British Columbia and Eastern Washington continued to be a problem for residents in the Puget Sound region and throughout Western Washington, Reedy said. It might have brought down temperatures, also.

Air quality reached unhealthy levels in the Cascade foothills Friday. It was considered unhealthy for sensitive groups in the Seattle and north Puget Sound areas. 

Those measures are based on the concentration of particles in the smoky air. Researchers pay close attention to particles smaller than 2.5 micrometers, which are tiny enough that about 20 are the width of a human hair, according to Carvlin.


Large particles — like visible ash — get filtered out by the nose and throat. But these smaller particles can cause damage. 

“The smaller they are, the further they can get into your lungs and the really tiny ones can pass into your bloodstream. They can get all around your body and produce systemic inflammation,” Carvlin said. 

Exposure to these particles puts people more at risk for respiratory disease. A peer-reviewed study published Friday in ScienceAdvances linked short-term exposure to wildfire smoke with increased likelihood of COVID-19 cases and death. 

“If you’re breathing in that smoke, it’s causing damage to your respiratory system,” Carvlin said. “You’ll be more susceptible to any virus or flu.”

Smoke can also affect the immune system. 

When the air is smoky, “your immune system is fighting that and not as able to respond to other invaders,” Carvlin said. 


Wildfire smoke and heat are both associated with cardiovascular disease. 

King County begins to see general health impacts from heat when temperatures are in or exceeding the mid-80s and when humidity percentages are in the 40s, according to Tania Busch Isaksen, a University of Washington researcher who has studied the impacts of heat here.

The extreme heat in June — which sent Seattle temperatures over 100 degrees for three straight days and reached 108 — contributed to the deaths of more than 100 Washingtonians, according to data from the state Department of Health.

COVID response hampered

Heat and smoke temporarily hampered the region’s coronavirus response. 

Drive-thru testing sites operated by Snohomish County were closed Friday and the county planned to do the same Saturday. Call center employees were busy directing people to testing sites at pharmacies and grocery stores, said Heather Thomas, a spokesperson for the Snohomish Health District. 

The temporary employees who work at those sites usually stand outside from morning to evening. 


The county-operated vaccine clinics also shortened hours Friday and Saturday. The county did not want the employees to be exposed for too long to heat and poor air quality.

“It just goes to show that even in spite of a pandemic, public health is still working on other things. We’ve got other issues happening around the county,” said Thomas.

Snohomish is currently considered at high transmission risk for coronavirus, she said. Hospitals across the state and country are at high capacity and officials recommend that people seek care at urgent care or walk-in clinics if possible.

Hospitals had not reported significant impacts from heat or wildfire smoke.

Harborview Medical Center had not seen an influx of patients due to the heat wave or wildfire smoke, said spokesperson Susan Gregg. Across UW Medicine’s four campuses, it had 65 COVID-19 patients. 

Public Health — Seattle & King County reported 13 heat-related visits to area emergency departments through Thursday. No one was hospitalized.


Getting by

Bethany Williamson, 59, lives in a house without air conditioning in Kirkland with three dogs, her husband and two kids. 

During the heat wave in June, all of them, except her son, spent the days in a bedroom with a portable air-conditioning unit, holed up watching TV. 

“The rest of us were just like slugs. We’re not doing anything,” she said.

The unit was able to keep the room just below 100 degrees, she said, but this week, the unit blew out. 

In June, Williamson said she could not find a single available hotel room. This time she was able to secure a room for Friday night. Williamson said her plan is to do facials with her 14-year-old daughter and enjoy the cold, smoke-free air. 

At home, she has the door cracked so there is a bit of a breeze but that means the smoky air has gotten in.


Normally she can see the Cascades from her backyard, but today all she can see is a pine tree. On Thursday night, she managed to sleep with the help of a ceiling fan, three standing fans and a floor fan aimed at the dogs in their crates. 

The increase in coronavirus cases and maskless people at stores concern her and she isn’t sure her daughter is going to be able to go back to school in the fall. “I thought to myself today, ‘I wonder if this is what it feels like to be under house arrest,’ ” she said.

Since she moved to the Seattle area in 1984, smoke and heat waves have become more common.

“It never used to be that way,” she said.

Looking forward

Smoky skies were expected to dissipate quickly with a return to moderate or even good air quality on Saturday, Carvlin said.

By Sunday, higher winds should clear out most lingering smoke, though haze from California fires higher in the atmosphere could soon arrive from the Pacific Ocean.

“It shouldn’t have an impact on the ground,” Carvlin said.

Even if the world reduces greenhouse gas emissions, researchers expect these simultaneous hazards to increase for years before the climate stabilizes, said Deepti Singh, a climate scientist and assistant professor at WSU Vancouver.

“In the next few decades, our temperatures will continue to warm, which means we’re more likely to see more frequent, larger and more severe heat waves like we saw this season and we’re also likely to see larger increase in risk for wildfires,” Singh said, citing the recent U.N. panel report on climate change.

Singh said it was critical to plan for future heat and smoke events by ensuring broad access to air conditioning and air filtration, including in low-income communities with less access today.