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 (98.6°F/37°C) to about 86°F/30°C.
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 68°F. 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 70°F 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 50°F/10°C water)
- Drown Proofing - 1½ hours
- Swimming slowly - 2 hours
- Treading water - 2 hours
- Holding still - 2¾ 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
2. Put on a PFD. Act quickly before you lose full use of your hands and
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
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
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
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.
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 . .-1°F Speech becomes slurred
- -2°F Fingers become clumsy, nub, weak and shiver
- Moderate . -3°F Feet loose strength, difficult to stand
- -4°F The brain affected, thinking becomes difficult
- Severe . . . -9°F Shivering is replaced by muscle rigidity
- -14°F Unconsciousness and heart becomes irregular
- -23°F Death from heart failure
Shivering, "goose bumps," hands may be numb with an inability to perform
fine motor skills.
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.
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 78°F and
pulmonary edema, cardiac and repertory failure may occur but death can
result before this happens. Death is imminent if breathing becomes shallow
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
- 5. Lay victim in a level face up position with a blanket or other insulation
- 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
- 9. Do not massage or rub the victim, rough handling may cause cardiac
- 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,
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!