Existing health problems may be aggravated by heat. Skin is cool and sweaty. The person is conscious and rational. Treatable by discarding clothing, resting and frequent drinking. A medical check-up and sometimes hospitalisation should follow immediately.
People are irritable, confused or apathetic.
Fits or loss of consciousness may occur. Skin is hot and dry because sweating has stopped. Treatable by very immediate cooling, removing all clothes, resting in a cool place, spraying with cool water and then fanning vigorously. Get the person to hospital immediately. This is a very serious condition.