Safety update

November 1995Dangers of hypothermia exposure

This safety update is for skippers and crew. It is issued to raise awareness of the potential serious risk to safety from hypothermia. It provides safe practice tips for how best to reduce the risks involved and how to alert people to the risk to safety from hypothermia.


Hypothermia, generally known as exposure, is defined as a general lowering of the central body temperature. This lowering of the central body temperature, if not checked, will quickly cause death. Survivors in lifeboats and liferafts and in the water are particularly susceptible to exposure.

Precautions and procedures

Skippers and crew should be fully aware of the dangers of hypothermia and have adequate knowledge of its prevention, symptoms, and treatment.

The Symptoms

  • Abnormal behaviour; at first aggressive and irrational. Finally; apathy and indifference.
  • Weariness and reluctance to move about
  • Unawareness of danger and a false feeling of well-being
  • Clumsiness and loss of judgement
  • Collapse and unconsciousness
  • Death

The period between first symptoms to unconsciousness may be as short as 30 minutes. PROMPT TREATMENT IS ESSENTIAL.

Safe practice tips


  • If it becomes necessary to abandon ship wear warm windproof clothing preferably covered by waterproof garments. Head coverings and gloves are important. Wear as many layers of clothing as possible and fasten them securely to the body. Warm clothing giving full protection to the whole body greatly increases the chances of survival. Even when saturated, layers of clothing give some protection against the cold.
  • In boats and rafts remain in shelter as much as possible.
  • Do not over-exert.
  • Eat energy food, such as chocolate, glucose, sweets, raisins, etc., and take liquids (except alcohol) whenever possible.


  • Get patient into most sheltered position and keep him lying down and as warm as practicable.
  • If patient's clothes are wet do all possible to get them changed for dry garments or blankets.
  • If patient is cold get a warmer person to lie close to him and warm him gradually.
  • Try to get patient to eat energy food or drink unless he is in a state of collapse when food and drink may cause vomiting and choking.
  • If breathing falters use mouth-to-mouth resuscitation.
  • If patient is, or has been, in state of collapse do not move him about for at least a day.
  • Do not give alcohol

The onset of the effects of hypothermia is much quicker if survivors are immersed in the water. Every effort must be made to rescue survivors from the water, quickly.

Original source content - Boat Notice 101995, November: Dangers of hypothermia exposure.

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