STAGES AND EFFECTS
SHORT-TERM IMMERSION: IMPAIRED FUNCTION
In cold water, a person may begin to experience the loss of basic motor skills after only a few minutes. Between 10 and 30 minutes after immersion, a person's hands quickly lose strength and sensation and subsequently the ability to swim (even strong swimmers). In cold water immersion cases, boaters often drown as a result of swimming failure before hypothermia ever has the chance to set in.
LONGER TERM IMMERSION: IMMERSION HYPOTHERMIA
Following 30 or more minutes of immersion, hypothermia - (a drop in body temperature below the normal level) will begin to set in. The overall body temperature will continue to drop until it reaches the same temperature of the water. Hypothermia symptoms range from mild to severe. As the body's core temperature falls, a person will eventually lapse into unconsciousness.
POST RESCUE COLLAPSE:
A drop in blood pressure may lead a person to become unconscious or to stop breathing at the point of rescue or up to several hours afterward.
A PERSON SUFFERING FROM HYPOTHERMIA SHOULD RECEIVE MEDICAL ATTENTION AS SOON AS POSSIBLE