As multiple wildfires burn across Canada and the western U.S., millions are being exposed to the dangers of smoke inhalation.

Heavy smoke from several large wildfires blazing in Canada and Minnesota is expected to engulf large swaths of the Midwest and Northeast U.S. this week, exposing millions of…

Fires in parts of Canada are blanketing several cities with smoke. Experts recommend limiting time outside, purifying indoor air and wearing a respirator if outside.