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.

Smoke from Canadian wildfires is causing air quality concerns for millions of Americans in the Midwest and Northeast. Air quality alerts were in effect Tuesday in several states, including Wisconsin,