Hypothermia and Cold Shock - The
Risks of Off Season Boating
by Pete Seidel,
ADSO-MS-GRU-MOR 1SR, USGC Aux.
The warm weather
boaters have left the water and are dreaming of the spring launching
season. The crowds are gone from the local waters during the colder
months of the year leaving only the wind to ripple the surface. A few
die-hard fishermen still work their favorite spots, enjoying the peace
and quiet. Bundled up against the cold, waterfowl hunters also take
advantage of the now nearly empty waterways. The crisp clear days of the
cold weather seasons are the best of times for many boaters.
Enjoying these good
times does not come without the risk of paying a heavy price. The water
is cold, with temperatures that have gone under 60? F., during the
off-season making a fall into the water a real danger of becoming a
fatal accident. His love of cold weather boating puts a winter boater in
a real risk of being in a man overboard situation that runs a very high
risk of becoming a fatality. The sharply reduced boating traffic adds to
that danger making an immediate or prompt rescue highly unlikely,
requiring that off-season boaters be doubly careful and avoid solo
trips.
The main objective is
to avoid entering the water because immersion in cold water rapidly
incapacitates and may quickly kill boaters who are not wearing
protective clothing. Surfers, sailboarders, kayakers and other folks in
similar sports wear wetsuits or drysuits to protect themselves from the
cold water. Smart off-season boaters, including sailors, fishermen,
hunters, and others take similar precautions to improve their safety
while on the water including never going out alone.
To properly prepare,
you have to first understand what happens to your body in cold water.
Water removes heat from a body 25 times faster than cold air and most of
the body heat is lost through the head. Swimming, thrashing about, and
other physical activity increases the heat loss through the limbs and
extremities. If you become a person in the water (PIW) you will sharply
reduce your survival time though physical activity. Strong swimmers
wearing a PFD have died before they covered 100 yards in cold water. Did
you know that in water with a temperature of less than 40? F., a strong
man can expire before he can swim 100 feet? Two factors come into play
against you while you are immersed in cold water; they are cold shock
and hypothermia.
Cold shock is the
body's reaction to the shock of cold water. During cold weather boating
all persons on board should wear life jackets. Cold shock from falling
into icy water can trigger an involuntary gasping reflex that will cause
you to inhale water through your mouth. Without a life jacket a person
can drown without ever coming back to the surface. Wearing your life
jacket will increase the likelihood of survival if you should
accidentally fall into the cold winter water. Cold shock may also result
in cardiac arrest. When the head and chest are exposed to cold water,
the result is often a very sudden increase in heart rate and blood
pressure. Cold water immersion can also result in immediate loss of
consciousness but, depending on the type of life jacket worn an
unconscious victim can survive without drowning.
Hypothermia in
layman's terms is decreased body temperature. This condition develops
more slowly than the effects of cold shock and you may not be
immediately aware of the symptoms. Remember that the symptoms of
hypothermia include shivering as the body loses heat and body
temperature drops, uncontrolled rapid breathing follows the initial
gasping response and may cause a loss of consciousness, muscle rigidity
and loss of voluntary motor function which results in physical
helplessness. A hypothermia victim starts to shiver as core body
temperature falls from 97?F. down to about 90?F. A person at risk of
hypothermia must try to control breathing rate to avoid hyperventilation
leading to unconsciousness following the immediate involuntary gasping
response to the initial immersion into cold water. Uncontrolled or rapid
breathing will speed up the chilling process. When the body's core
temperature falls to 93?F. physical ability is severely diminished and
mental capacity begins to deteriorate rapidly. A victim usually falls
into an unconscious state when body temperature falls to 86?F. If the
victim doesn't drown first, hypothermia will finish him off when the
body temperature falls to or near 80?F. Survival figures show that an
adult dressed in average clothing may remain conscious for one hour in
water at 40?F, and perhaps as long as 2 - 3 hours in 50?F water.
Remember, any movement in water accelerates body heat loss. The recent film,
Titanic, graphically portrayed the fatal effects of lowered body
temperature on persons in the water.
Avoid venturing out
onto the cold wintry waters alone, because a buddy can save your life,
or vice versa. If you find yourself in cold water, try to get back in or
on your boat immediately. If the boat capsizes, do not leave the boat
because the overturned boat is easier to spot than a single person in
the water. If you are not wearing thermal protection and you can't get
out of the water, keep as still as possible. Fold your arms against your
chest, cross your legs to reduce the amount of cooling surface. Rely on
the buoyancy of your life jacket and float quietly until help arrives.
If two or more people are in the water, huddle close together. Put your
arms around each other to slow down heat loss. Stay together and stay
still, letting your life jackets keep you afloat.
Planning for cold
weather off-season boating is essential. Wear clothing that will protect
you in the event of cold-water immersion. Always wear your personal
flotation device. On land, conventional wisdom advises that you wear
layers of warm clothes. On the water this will not help you. The shore
side winter clothes will not be effective in retaining your body heat.
You can wear layers of clothing under or inside a waterproof shell. An
effective cold-water outer suit is a waterproof fabric with neoprene
waterproof gaskets at the wrists, neck, waist and ankles. Survival
suits, like the Stearns and Mustang types, are available from local
boating equipment retailers or though catalogs. You can also wear
cold-water survival suits under your regular clothes. These suits are
worn by windsurfers and river paddlers and are similar to a divers dry
suit.
As you plan your trip
you should pack dry clothing in a waterproof bag. Make sure that your
boat has adequate bailing equipment. You may want to make provisions to
facilitate re-entry into your boat by having a boarding ladder or even a
rope overside. Your life jacket should have a sound producing device
such as a whistle or horn and a reflective device attached to it. Before
you leave home check the weather forecast for the day because a cold
rain can soak you and bring on hypothermia almost as fast as a dunking.
Prepare a float plan and leave it with someone, or at least notify
someone where you are going and when you expect to be back. When you
return let them know you're back. Never go out alone. Using the buddy
system is a proven lifesaver. While you are out, observe the boats
around you, their location and proximity to your boat. On cold water,
you have to depend on each other for quick rescue in case of an
accident. You know, you watch them and they watch you and you help each
other out.
If you are going out
into cold weather situations, whether on the water or on land, you may
run into someone who is experiencing hypothermia. You might be able to
save that person's life by knowing the right way of providing first aid.
Hypothermia First
Aid
The victim shivering,
but coherent, indicates mild hypothermia symptoms. Move victim to place
of warmth. Remove wet clothes; give warm, sweet drinks; NO alcohol or
caffeine. Keep victim warm for several hours.
Moderate hypothermia
symptoms include reduced body temperature with shivering decreased or
stopped. Victim may seem irrational with deteriorating coordination.
Treat same as above but no drinks. Victim should be kept lying down with
torso, thighs, head and neck covered with dry clothes, coats, or
blankets to stop heat further heat loss. Seek medical attention
immediately.
Severe hypothermia
symptoms show shivering probably stopped; victim resists help or may be
semi-conscious to unconscious. Victim must be kept prone, on back and
immobilized. Cover torso, head, neck and thighs with dry covers to stem
further heat loss. Do not stimulate arms and legs in any manner. Cold
blood returning to the body core may cause cardiac arrest. Get medical
help immediately.
Once removed from the
water, victim appears dead, no breathing or pulse apparent and body is
rigid. Assume victim can be revived. Apply dry clothing or covers like
above. Look for signs of pulse or breathing during first two minutes. If
pulse or breathing is found, even in trace amounts DO NOT start CPR. In
this state, CPR can cause cardiac arrest. If you can't find a pulse or
sign of breathing, CPR should be started only by a trained and qualified
crewmember. Rush victim to nearest medical facility by best means
available.
Cold weather boating has its rewards for
the prudent mariner. Following a few simple rules will help keep your
safe, or at least increase your chances of returning home. Wear warm
clothing. Wear a PFD at all times. Every year we read and hear about the
'experienced boaters' that die in cold weather boating accidents. Nearly
every one of those missing mariners was not wearing a flotation device.
File a float plan. Never go out alone. Check the weather before leaving
home. While on the boat keep an eye on the weather and know when to quit
and head for home. Even in cold weather, leaving the dock is optional,
but returning is mandatory.