Moderate. Unusually sensitive people should consider limiting prolonged outdoor exertion
Orange
Unhealthy for sensitive groups. Active children and adults, and people with respiratory disease, such as asthma, should limit prolonged outdoor exertion.
Red
Unhealthy. Active children and adults, and people with respiratory disease, such as asthma, should avoid prolonged exertion. Everyone else, especially children, should limit prolonged outdoor exertion.
Purple
Very Unhealthy! Active children and adults, and people with respiratory disease, such as asthma, should avoid all exertion. Everyone else, especially children, should limit prolonged outdoor exertion.