As more than 800 active fires continue to burn across Canada, smoke has descended on parts of the U.S. For those who are more sensitive to smoke or are in a hig

As more than 800 active fires continue to burn across Canada, smoke has descended on parts of the U.S. For those who are more sensitive to smoke or are in a high-risk group, wearing a mask can help protect you -- as long as it's the right kind of mask. [↧](https://t.co/4qt…