What is hypothermia?
Hypothermia is a physical condition that occurs when the body’s core temperature falls below a normal 98.6° F (37° C) to 95° F (35° C) or cooler. Think of hypothermia as the opposite of heat stroke. Cold water dangerously accelerates the onset and progression of hypothermia since body heat can be lost 25 times faster in cold water than in cold air. Hypothermia affects the body’s core – the brain, heart, lungs, and other vital organs. Even a mild case of hypothermia diminishes a victim’s physical and mental abilities, thus increasing the risk of accidents. Severe hypothermia may result in unconsciousness and possibly death. About 600 people in the U.S. die of hypothermia each year.
via Hypothermia Prevention: Survial in Cold Water | Minnesota Sea Grant.