Hypothermia is a lowered body temperature less than 95 degrees F. Cold water near-drowning is considered a submersion accident often leading to unconsciousness or coma in water temperatures of 70 degrees F or less. A long submersion time is considered 4 to 6 minutes or greater.
Hypothermia may be mild, moderate, or severe. The presentation may range from shivering and piloerection ("goosebumps"), to profound confusion, irreversible coma and death. Significant hypothermia begins at temperatures of 95 degrees F and below. The lowering of the body temperature occurs as the body is robbed of heat by the surroundings.
Water conducts body heat away up to 26 times faster than air of the same temperature. Normal body functions slow down with decreasing heart rate, decreasing respiratory and metabolic rate. Thinking is impaired and speech becomes confused. Reflexes are slowed and muscles become stiff and unusable. Then dangerous life-threatening heart rhythms develop which are hard to reverse.
Hypothermia is the opposite of hyperthermia, the condition that causes heat exhaustion and heat stroke.
Hypothermia describes a state in which the body's mechanism for temperature regulation is overwhelmed in the face of a cold stressor. All survivors should know that hypothermia is a potential killer.
