ABSTRACT
Aviation heat strain risk can be predicted using heat stress indices. Pre-takeoff phase may be the most thermally stressful. Most insulation from cold weather clothing comes from air trapping. Heat loss is much greater in water than air; a dry immersion suit is required whenever there is risk of ditching in cold water. Training improves effectiveness of general principles of survival: protection, location, water, food. Cold threat occurs mainly on the ground before/after flight or following abandonment. Risks include hypothermia, cold injury and cold shock/drowning. Water represents a greater threat because of its higher thermal conductivity and specific heat. Cooling power of the environment is the result of air temperature, air movement or movement through air. Hazards of water immersion can be considered in three phases: cold shock, underwater escape, swim failure. Sudden immersion in cold water causes cold shock which results in: an inspiratory gasp, severe hyperventilation and hypertension.
