Oregon residents are advised to stay indoors as air quality deteriorates to unhealthy levels in several areas. The Environmental Protection Agency's AirNow map indicates that central Oregon, particularly near Sisters and Bend, is experiencing 'very unhealthy' air quality due to smoke from prescribed burns. Air Quality Index (AQI) readings indicate high levels of PM2.5, a fine particulate matter that can penetrate deeply into the lungs and bloodstream. This poses significant health risks, especially for individuals with pre-existing heart and lung conditions, children, and the elderly.