If there are poisonous substances in the air, these will be breathed in. Thick smoke causes the muscles lining the airways to go into spasm; the victim begins to choke and suffocate. Carbon monoxide (from vehicle exhausts) replaces oxygen in the blood, causing oxygen deficiency in the tissues. Other gases, such as those given off by burning foam rubber and other plastics, are toxic and can cause paralysis of the muscles involved in breathing.
Someone who has inhaled a poisonous chemical fights for air, goes cherry-pink in the face, becomes confused, complains of a headache, and may eventually become paralysed and unconscious.
The first thing to do is to remove the person from the chemical fumes or contaminated area without exposing yourself to danger. Give artificial respiration and cardiac resuscitation if necessary (see Breathing, Circulation ), and place in the recovery position (see Unconsciousness ) so that the airway is open. Then dial 911 or any emergency telephone number in your country.