Using recirculate mode on my car's ventilation system dramatically lowered the PM2.5 levels inside. Try it out if you're starting to feel that burning/choking feeling.
Many of you in the US Northeast and Central Canada are waking up to the worst air quality in the world (from wildfires). Here is some advice to get through the next few days: - Avoid running, cycling, outdoor sports and strenuous yard work while the air is bad.