Hana Hou logo
THE HANA HOU SERIES
Hypothermia
1999 Kawika Sands

Hypothermia is subnormal body temperature, a lowering of the body core temperature. When you lose enough body heat, you become hypothermic. Cold water robs the body of heat 25-30 times faster than air. Depending on the waters' temperature, 10 or 15 minutes, your core body temperature (brain, spinal cord, heart, and lungs) begins to drop. Your arms and legs become numb and useless. You may lose consciousness and drown before your core temperature drops low enough to cause death. Unconsciousness can occur when body core temperature drops from normal (98.6F/37C) to about 86F/30C. Safety experts estimate that half of all drowning victims die from the fatal effects of cold water, not from water filled lungs.

Hypothermia can be fatal and occurs in most survivors extracted from water under 68F. Cold water does not have to be icy, just colder than you are to set water hypothermia in motion. A person who is wet, improperly dressed and intoxicated can become hypothermic in 70F weather. The rate of body heat loss depends on water temperature, the clothing worn, percent body fat and other physical factors, and most importantly the way you conduct yourself in the water:

Predicted Survival Time (average adult in 50F/10C water)
Drown Proofing - 1 hours
Swimming slowly - 2 hours
Treading water - 2 hours
Holding still - 2 hours
H.E.L.P. position - 4 hours
Huddle - 4 hours
Wearing a PFD - 7 hours

Body Hot Spots
Certain areas of your body are "hot spots" that lose large amounts of heat faster than other areas. These hot spots need special protection against heat loss. The head and neck are the most critical areas. The sides of the chest, where there is little fat or muscle, are major areas of heat loss from the warm chest cavity. The groin region also loses large amounts of heat because major blood vessels are near the surface.

SURVIVING IN COLD WATER
1. Minimize body heat loss. This is the single most important thing you should do. Do not remove clothing, instead, button, buckle, zip and tighten collars, cuffs, shoes and hoods. Cover your head if possible. A layer of water trapped inside your clothing will be slightly warmed by your body and help insulate you from the colder water, slowing your rate of body heat loss.

2. Put on a PFD. Act quickly before you lose full use of your hands and limbs.

3. Getting out of the water. Climb onto a boat, raft, or anything floating. Right a capsized outrigger and climb in. Most outriggers will support you even if full of water. If you can not right a capsized outrigger climb on top of the hull. The object is to get as much of yourself out of the water as possible.

DO NOT SWIM!!!
Unless it is to reach a nearby boat, another person, or a floating object on which you can climb. Unnecessary swimming "pumps" out warmed water between your body and your clothing circulating new cold water to take its place. Unnecessary movement of your arms and legs pumps warm blood to your extremities, where it cools quickly, reducing your survival time by as much as 50%!

If you can't get out of the water try one of the following survival techniques:
1. Heat Escape Lessening Position (H.E.L.P). hold knees to chest to protect trunk of body from heat loss. Wrap arms around legs and clasp hands together.

2. Huddle. Huddling together with 2 or more people will extend survival time 50% longer than swimming or treading water.

3. Remain still. However painful, intense shivering and severe pain are natural body reflexes in cold water which will not kill, you but heat loss will.

HYPOTHERMIA SYMPTOMS
Watch for the "Umbles." Stumbles, fumbles and grumbles. These may indicated the brain is being effected by cold being pumped through it.

Symptoms include intense shivering, loss of coordination, mental confusion, cold & blue (cyanotic) skin, especially around lips or fingers, weak pulse, irregular heartbeat and enlarged pupils. Once shivering stops, core body temperature begins to drop critically.

Core Body Temprature Loss
Mild . .-1F Speech becomes slurred
-2F Fingers become clumsy, nub, weak and shiver

Moderate . -3F Feet loose strength, difficult to stand
-4F The brain affected, thinking becomes difficult

Severe . . . -9F Shivering is replaced by muscle rigidity
-14F Unconsciousness and heart becomes irregular
-23F Death from heart failure

Mild Hypothermia
Shivering, "goose bumps," hands may be numb with an inability to perform fine motor skills.

Moderate Hypothermia
Intense shivering, coordination is slow or labored with mild confusion. If the victim cannot walk 30 feet in a strait line he is moderately hypothermic. Later stages include persistent or violent shivering, slurred or difficult speech, dizziness or sluggish thinking or amnesia, fumbling or impaired gross motor movement and an inability to use hands, and irrational behavior or disinterest or depression.

Severe Hypothermia
Shivering may occur in waves with the pauses getting longer. Skin is blue or pale and puffy. Very little muscle coordination. Confusion, incoherent/irrational behavior (but the victim may LOOK aware). Muscle rigidity. Semiconsiousness, loss of awareness, pupils may have dilated. Decreased heart rate and heart fibrilation (victim may appear dead), then unconsciousness. By the time the core temprature is down to about 78F and pulmonary edema, cardiac and repertory failure may occur but death can result before this happens. Death is imminent if breathing becomes shallow and erratic.

HYPOTHERMIA FIRST-AID
Any person pulled from cold water should be treated for hypothermia and ignore protests from the victim. Your goal in treating hypothermia is to prevent further body cooling. Severe cases call for rewarming by trained medical personnel. In all cases, arrange to have the victim transported to a medical facility immediately.

1. Gently move the victim to warm shelter.

2. Check breathing and heartbeat very closely for as long as two minutes.

3. Start CPR if necessary.

4. Remove victim's clothing with a minimum of movement, cut them away if necessary.

5. Lay victim in a level face up position with a blanket or other insulation beneath them.

6. Wrap victim in warm blankets, sleeping bag or other warm covering.
If there will be a long delay before victim arrives at a medical facility use the following rewarming techniques. Take all wet/cold clothes off and wrap the person in the blanket. Use the tarp/plastic and the survival blanket to insulate the victim from the ground or keep him dry.

7. Apply heating pads or hot water bottles (wrapped in a towel to prevent burns) to the head, neck, chest, and groin.

8. Do not apply heat to arms and legs or give them a hot bath. This forces blood out through the cold extremities and back to the heart, lungs and brain, which will further drop the core temperature. This can cause "after drop" which can be fatal. Apply the hot packs at the neck, kidneys and crotch (do not apply directly, the hot packs can become VERY hot and injure the victim!).

9. Do not massage or rub the victim, rough handling may cause cardiac arrest.

10. You may apply warmth by direct body to body contact. Have someone remove their own clothes and lay next to victim skin to skin. Wrap both in blankets (note: do NOT do this if the victim is TRULY hypothermic or you may have TWO victims).

11. If person is alert enough you can give them hot drinks (NO caffeine or alcohol!). If they are unconscious or stuporous do not give them anything to drink. It's normal for the person to want to urinate (you may have to help) but keep giving water (warm if possible, hot would be better), soup, anything HOT.

COLD WATER DROWNING
Some apparent drowning victims may look dead, but may actually still be alive! A phenomenon called the "mammalian diving reflex" can be triggered by cold water. This reflex, common to whales, porpoises and seals, shuts off blood circulation to most parts of the body except the heart, lungs and brain and slows the metabolic rate. What little oxygen remains in the blood is circulated where it is needed most. Do not assume that a person who is cyanotic and who has no detectable pulse or breathing is dead. Administer CPR and transport the victim to a medical facility as quickly as possible for specialized rewarming and revival techniques. People have been revived after having been submerged for extended periods, some in excess of 45 minutes! So DON'T GIVE UP!

Part 3<< -|- Index -|- >> Part 5

Hele on to Canoe Club News

Last Modified: Saturday - 19991113.10:01 EST
Copyright 1999 Kawika Sands
Produced online by HoloHolo Internet Publishing all rights reserved