Smoke from numerous Canadian wildfires is again impacting the Philadelphia region this week, with environmental authorities issuing code orange air quality alerts largely in effect through Tuesday as a result of the blazes’ aftermath settling in on the area.

Americans in at least 10 states in the Upper Midwest and Northeast are under air quality alerts stemming from Canadian wildfires funneling smoke into the United States. It comes as millions across the South and Southwest face even more sweltering heat.