What can wildfire smoke this thick do to a healthy person? Once the AQI climbs above 300, even people without asthma or heart disease can experience airway inflammation, reduced lung function, chest tightness and trouble breathing. At 500, the air is considered hazardous for everyone. And 1,000? That is literally beyond the official AQI scale. #airquality #smoke #wildfires #wildfiresmoke #canadianwildfire