Air quality in Central Washington prompted Chelan County officials to begin handing out free masks on Thursday morning.
Inhaling wildfire smoke can be dangerous and irritate your eyes, nose, throat or lungs.
The Washington State Department of Health recommends staying indoors and reducing physical activity in smoky conditions.
If you're extremely bothered by the smoke, the DOH said a mask called a "particulate respirator" can help protect your lungs.
Use: N95 or N100 with two straps that can go around your head.
Don't use: One-strap paper dust mask, a surgical mask, a bandana, towel (wet or dry), or tissue.
Using respirator masks can make breathing more difficult, so check with your doctor if you already have a lung or heart disease.
The DOH said respirator masks shouldn't be used on young children or people with beards because they don't seal well.
Learn more about protecting yourself from the Department of Health.
© 2017 KING-TV