Air quality has taken a serious hit across the United States as a twofold blow of wildfires in the West and in Canada have sent smoke pouring across large sections of the country — a problem that’s set to linger for days.

Wildfire smoke from the Bear Gulch Fire is affecting air quality across western Washington. Prolonged exposure to smoke can harm lungs, especially for vulnerable groups like children and seniors. Experts advise staying indoors, using masks, and checking air quality updates online for safety.

Canada is battling more than 700 active wildfires across the country, roughly two-thirds of which are burning out of control, according to the Canadian Interagency Forest Fire Center (CIFFC). Smoke billowing from the blazes has blanketed central Canada and the northern U.S., prompting widespread air quality alerts.