Determines nature and extent of illness or injury, or magnitude of catastrophe, in order to establish the basic life support procedures needed to be followed, basing decisions on statements of persons involved, the examination of victim or victims, and knowledge of the emergency medical practice. Administers prescribed treatment at the site of an emergency, or in specially equipped vehicles, performing such activities as first aid, immobilization of injuries, application of splints, administration of oxygen, treatment of minor wounds or abrasions, or administration of basic life support procedures.