If your ship ever goes to cold
countries, you should undoubtedly have heard of Hypothermia.
If you haven't, you should learn something about it. Your very
life may depend on knowing the information below:
Hypothermia is a condition marked by an
abnormally low internal body temperature. It develops when
body heat is lost faster than it can be replaced. Normal
muscular and cerebral functions become impaired and death can
follow if it becomes worse. This takes place below 96º F and
Signs of hypothermia include confusion
or sleepiness; slurred speech or shallow breathing; weak pulse
or low blood pressure; stiffness in the arms or legs or poor
control over body movements. Severe hypothermia can cause an
irregular heartbeat, leading to heart failure and death.
- Shivering is typically the first sign of hypothermia.
It eventually becomes uncontrollable. However with
severe hypothermia, shivering stops. One of the key indicators
that the victim has moved from mild/moderate hypothermia to
severe hypothermia is that he/she is no longer shivering.
- Behavior changes like complaining, difficulty
in speaking, and uncoordinated movements. Victims will struggle to perform simple tasks
like walking a straight line or zipping up their coat.
With severe hypothermia, behavior changes from erratic to
apathetic to unresponsive. Uncharacteristic behavior like inappropriate excitement or lethargy, poor
judgment, and poor decision making are common.
- Cold, pale and blue-gray skin due to constricting blood
vessels. May develop into a coma, with dilated pupils making
it difficult to
determine if the victim is alive or dead.
How Heat is
Lost from the Body
- Convection: Heat is carried away from
the body by currents of air or water.
Wind chill is an example
- Conduction: Transfer of heat between two contacting
surfaces. Water conducts heat 25 times faster than air and
steel is even faster than water. Generally conductive heat loss accounts for only about 2% of
overall loss. However, with wet clothes the loss is increased
- Evaporation: Heat loss when water is removed from the body
during sweating and respiration.
- Radiation: The loss of radiated heat from a warm body to a
surrounding colder environment. This is
more significant on cold, cloudless nights. Factors important in
radiant heat loss are the surface area and the temperature
It is important to recognize the strong connection between
fluid levels, fluid loss, and heat loss. As the body moisture is
lost through the various evaporative processes the overall
circulating volume of water in the body is reduced, leading to
dehydration. This decrease in fluid level makes the body more susceptible to
Field Treatment for
The basic principles of re-warming a hypothermic victim are to
conserve the heat they have and to replace the body fuel they
are burning up to generate that heat.
Prevention of Hypothermia
- Reduce Heat Loss.
Find shelter from the wind, and cold. This
could be under a tree, in tent, or in a sleeping bag. If at
all possible, get the victim off of the ground (a foam pad
would be ideal). Remove any wet clothing and replace with
layers of dry clothing, increased physical activity.
- Add Fuel and Fluids. Keep a hypothermic person adequately
hydrated and fueled. Give them warm, sweet liquids but NO coffee
or tea - and NEVER ALCOHOL!
- Alcohol - a vasodilator - increases peripheral heat loss
- Caffeine - a diuretic - causes water loss increasing
- Tobacco/nicotine - a vasoconstrictor, increases risk of
- Provide Heat Source. Light a fire or a stove.
- Seek Medical Attention as quickly as possible. Never leave
a hypothermic victim alone.
Appropriately. Wear clothing to keep the warmth. Avoid
- Stay Dry - be aware that water comes from both the outside
(environment) and the inside (perspiration).
Stay out of the
wind if possible.
- Keep Your Body Burning. Stay hydrated, and eat foods
like carbohydrates and proteins to provide energy.
- Conserve Your Energy.
Exhaustion leads to a quicker onset of hypothermia.
If you fall overboard, is it better to swim or not to swim?
Consider your circumstances carefully before deciding to swim.
- Swimming is an option but this leads to faster heat loss and
- Even a strong swimmer would not be able to swim
more than one kilometer in calm water. Cramp and hypothermia
develop more quickly, usually a victim becomes semiconscious
and is likely to drown.
- Swimming increases heat loss (increase by 35-50%) and is not
recommended if you are more than one kilometer away from
shore. Adopt a heat conserving strategy (help or huddle)
- Treading water also leads to rapid heat loss. Avoid if possible.
Wear a PFD (Personal Floatation Device) Do not remove clothing or
shoes, they provide insulation (a jacket can also be used to trap air and
It's important to keep warm and dry during the
windy, cold, winter
months. Dressing appropriately can make a big difference. Wear
several loose, warm layers. Thick wool socks and a cap can
combat winter's chills. At night, use extra blankets because
hypothermia can develop during sleep.
Thermal underwear are
excellent for keeping the heat in your body.
Get plenty of rest. Fatigue makes you more vulnerable to
subnormal heat and cold. Eat nutritious foods, and exercise
moderately. Limit your alcohol intake because alcohol speeds
up body heat loss.
I hope this information will serve you well when you travel
to the extremely cold regions of the world.
Marine Engineer World
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