Hypothermia is a medical event that occurs when a person's body core temperature drops below 95 degrees. This can be caused by exposure to water, wind, very cold air or all of the above. A decrease in critical body heat can result in a loss of dexterity, poor mental state, a loss of consciousness and eventually death. A few minutes in cold water makes it very difficult to swim, or even to stay afloat. Also, the sudden shock of hitting cold water can cause a reflexive "gasp" allowing water to enter the lungs, so that drowning can be almost immediate.