Hypothermia is when your body looses heat more rapidly than it can replenish it.

More information on Hypothermia (With Links to Videos) / Cold Water Boot Camp

SYMPTOMS: (Not all symptoms need to be present.)

A) Vigorous shivering.

When shivering stops will have advanced to (H) intoxicated or euphoric.

B) Clouding of mental capacity.

Impaired mental judgment (may vary from mild to severe), impaired speech, poor coordination, disoriented.

C) Muscular rigidity.

Movements may be unsteady, normal movements impaired, may selectively affect extremities (hands and arms when steering), numbness

D) Diminished breathing rate.

E) The skin may be cold to the touch or the lips can be blue.

F) Pupils dilated.

G) Pulse weak, slow, may be irregular.

H) A victim may appear to be intoxicated.

May also be an euphoric or don’t care state.


A) Remove victim from the cold environment, avoid rough handling (hypothermia victims are fragile).

Do not postpone treatment even if a person is removed from the cold environment.

Treat for hypothermia if there is any doubt that a person is a victim.

B) Remove or replace wet clothing if dry clothes or blankets are available.

Cut the cloths off if necessary – even gentle handling can injure someone that is hypothermic. Do not remove wet clothing if dry clothing is not available.

C) Have the victim rest in a warm, dry place.


D) Lay an unconscious or semiconscious victim face up.

E) Insulate the victim from further heat loss by wrapping them in a blanket.

F) Do not offer the victim food or drink.

G) Treat the victim for shock and transport to the nearest medical facilities as quickly as possible.

If any doubt exists as to the treatment or symptoms contact emergency personnel – both 911 and the Coast Guard have the ability to provide medical assistance over the radio or phone.

If an injury is life threatening contact the Coast Guard for assistance – depending on the speed of your vessel they can arrange for emergency personnel to meet your vessel or arrange for evacuation of a victim from your boat.


Hypothermia can kill at temperatures well above freezing.

Hypothermia occurs most rapidly when the body is immersed in cold water.

50 – 50 Rules

You have a 50 – 50 chance of swimming 50 yards in 50 degree water.
You have a 50 – 50 chance of surviving 50 minutes in 50 degree water.

Wear warm cloths.

Hypothermia can happen any time of the year. When on the water the temperature and wind can have a chill factor that surprises people by the severity. This means that hypothermia can sneak up on a sunny summer day as well as the winter.

Take more warm cloths and layers than you anticipate. Wind breakers and water proof combination’s.  All on the water activities can be wet, you can be splashed by wave action.

Heat loss is greatest for the head. Wear warm head gear even if it looks geeky. In cool weather the body will maintain the temperature of the brain and shut down circulation to the other extremities.

“Jacket” or “Vest” type life jackets provide extra warmth both in and out of the water. When in the water it helps to trap a warm layer of water next to the skin and also reduces the energy required to stay afloat.

Test show the heat loss of an average person treading water is 34% faster than a person holding still in a life jacket.

If you are in a boat that capsizes – stay with the boat and climb up on if possible – this reduces heat loss and a boat is a larger target for rescue personnel to see.

Wear clothing that is warm even when wet or moist (wool or synthetics such as polypropylene – fabrics such as cotton have a high heat loss rate when wet or sweaty)

Move as little as possible when in the water – movement will cause higher heat loss – keep arms and legs close to the body.

The chance of suffering from hypothermia can be increased by fatigue, alcohol or lack of food.

Alcohol can make hypothermia worse. Alcohol causes a false warmth and INCREASES heat loss.

Do not give a hypothermia victim alcohol. Alcohol can cause the normal constriction of veins to relax and let a large amount of cold blood to the interior of the body – this can cause a heart attack or the core temperature to fall low enough to kill a hypothermia victim that would otherwise survive.

When watch standing, crew members should watch each other and check for signs of hypothermia and fatigue. Crew members should be rotated to warmer or more sheltered areas to help prevent hypothermia.

Formatted for Printing (PDF):


© 2000 – 2010 http://www.captnmike.com

This entry was posted in Safety Thoughts, Sailing and Boating Skills and tagged , , . Bookmark the permalink.

1 Response to Hypothermia

  1. Pingback: Useful Web Sites and Information for Boaters and USCG Auxiliary Members | Boating Safety Tips, Tricks & Thoughts from Captnmike

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.