Air quality has taken a serious hit across the United States as a two-fold 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.

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.

At least three people have been injured and hundreds of homes and businesses are at risk in California as a massive wildfire spreads across the Los Padres National Forest. Smoke blowing over Las Vegas from the California wildfire created a hazy sky and poor air quality over Sin City Monday.