As hundreds of wildfires burn across Canada, smoke is traveling south and potentially affecting Americans’ health. Here's why it can be so dangerous.

The smoky scene calls to mind the record-shattering Canadian wildfire summer of 2023, with smoke that choked Michigan and much of the U.S. for days at a time. Researchers say wildfire smoke is becoming a more regular part of Michigan summers.

Dr. Ulep recommends wearing an N-95 mask when spending time outdoors if the air is polluted to that level. To stay healthy indoors, Dr. Ulep recommends keeping windows and doors closed and holding back from activities like smoking.