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 TM 55-1905-219-14-2
2-209. LIFE BOATS (Cont).
Even when the water temperature is as high as 70 (21 ), a man may remain in the water for a limited time only. A
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gradual fall in body temperature will take place, and the blood volume will decrease because of the transmission of blood
fluid to the tissues when the temperature falls. If not enough clothing is worn or if the clothing becomes wet, all possible
measures should be improvised on the boat to try and keep clothing dry in cool weather. When you abandon ship, take
with you as much clothing as possible, especially waterproof clothing and heavy undergarments. Huddle together for
warmth. Water on the floor of the boat should be carefully sponged out whenever practicable.
Food and exercise increase body heat production and are of value in protection against cold. Alcoholic beverages
should not be consumed for their use causes loss of body heat; and the blood vessels at the surface of the skin dilate,
which allows the heat to escape.
Alcohol also causes the loss of body water as urine, and the endeavor aboard a raft is to conserve the water supply.
Even in tropical waters with the temperature above 80 (26 ) aboard a life boat you will feel cold at night if your
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clothing is wet, and this chilling will interfere with your sleep and accelerate exhaustion. Therefore, every effort must be
made to dry clothing before nightfall. You are advised to exercise if you cannot keep warm otherwise.
Even though the body may be protected sufficiently to combat generalized chilling, the hands or feet of survivors may be
damaged. Frost- bite and immersion foot are the common types of serious injury resulting from such over-exposure.
Survivors whose body temperatures have been lowered to levels which can be fatal should be rapidly rewarmed.
IMMERSION FOOT - Immersion foot is the swelling of the feet accompanied by numbness and pallor or purplish
discoloration; it may finally lead to gangrene and loss of part of the foot. The hands may be affected by the same
disease; however, this is less common. The manner in which this injury is caused is not completely understood, but an
important cause is interference with blood circulation in the legs due to the combination of cold and cramped position.
With ordinary foot gear, which does not protect the feet from wetting, the condition commonly occurs when temperatures
of the water are below 50 , (10 ). The lower the temperature the more rapidly it occurs.
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Generally, rapid injury to the feet occurs only in water at below 50 (10 ), but occasionally injury occurs to feet that
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have been immersed for long periods of time (many days) in water of considerably higher temperatures (as high as 70
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(21 ). If you wish to prevent Immersion foot, promote circulation of the blood and keep the feet warm. Exercise the
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ankles and toes for several minutes, several times a day. Keep the feet elevated as much as is possible. Avoid
constriction of the limbs by tight clothing. If shoes become too tight, unlace them. If necessary, take them off. The feet
should, of course, be kept out of water for it is of the greatest importance to keep the feet dry to prevent cooling.
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