"Very Unhealthy" AQI is 201 to 300. This would trigger a health alert signifying that everyone may experience more serious health effects. "Hazardous" AQI greater than 300. This would trigger a health warnings of emergency conditions.
the Middle Ages or medieval period lasted from the 5th to the late 15th century. It began with the fall of the Western Roman Empire and transitioned into the Renaissance and the Age of Discovery
