and Cold Water Survival
As we go into the winter months and the air temperature cools below freezing,
the river water also cools. The warm bathwater we experienced in August has
become a faded memory.
According to Army Corps of Engineers
Data, the Ohio River at Markland, for example, cooled
from 65 degrees F on December 1st to 46 degrees on
December 15th, with the Pittsburgh (Emsworth) temps
already dropping below 40. Obviously, it will be near
freezing by the time February rolls around.
Above, a Navigation
Temperature Plot, available from the US Army Corps
of Engineers (link)
The question becomes, how does this affect you or your passengers if somebody
finds themselves unexpectedly in the water. Even if your only winter activity
is a quick walk along the dock, take a moment to consider your physical condition
and plan for how you would handle an emergency. Nobody plans to fall in,
but it happens.
The following information is reprinted
with permission from the United States Search and Rescue
Task Force (link):
Cold Water Survival
What is it? It is difficult even for
an expert to define. It is estimated to be around and
under the temperature of 70 degrees. However, this
will vary in each case due to the specific circumstances
and physical condition of the person involved.
What Happens In Cold Water?
Many of the fatal boating accidents
occur in the "out-of-season" months when
the water is cold. What happens to the body when suddenly
plunged into cold water?
The first hazards to contend with
are panic and shock. The initial shock can place severe
strain on the body, producing instant cardiac arrest,
as happened to a 15 year old scout in the month of
March in Pennsylvania several years ago.
Survivors of cold water accidents
have reported the breath driven from them on first
impact with the water. Should your face be in the water
during that first involuntary gasp for breath, it may
well be water rather than air. Total disorientation
may occur after cold water immersion. Persons have
reported "thrashing helplessly in the water" for
thirty seconds or more until they were able to get
Immersion in cold water can quickly
numb the extremities to the point of uselessness. Cold
hands cannot fasten the straps of a lifejacket, grasp
a thrown rescue line, or hold onto an over-turned boat.
Within minutes, severe pain clouds rational thought.
And, finally, hypothermia (exposure) sets in, and without
rescue and proper first aid treatment, unconsciousness
and death. We all recall the incident in which the
airliner went down in the dead of winter in the water
in Washington, D.C. several years ago. The vivid video
of the rescue attempts and those that died due to hypothermia
is not easily forgotten.
Normal body temperature of course,
is 98.6. Shivering and the sensation of cold can begin
when the body temperature lowers to approximately 96.5.
Amnesia can begin to set in at approximately 94, unconsciousness
at 86 and death at approximately 79 degrees.
What To Do In The Water
Cold water robs the body's heat 32
times faster than cold air. If you should fall into
the water, all efforts should be given to getting out
of the water by the fastest means possible.
Persons boating in the cold water
months should be thoroughly skilled in rescue and self-rescue
techniques. Most accidents involve small boats which
with practice, can be righted and re-entered. Most
boats, even filled with water, will support the weight
of its occupants. If the boat has capsized and cannot
be made right, climb on top of it.
Physical exercise such as swimming
causes the body to lose heat at a much faster rate
than remaining still in the water. Blood is pumped
to the extremities and quickly cooled. Few people can
swim a mile in fifty degree water. Should you find
yourself in cold water and are not able to get out,
you will be faced with a critical choice - to adopt
a defensive posture in the water to conserve heat and
wait for rescue, or attempt to swim to safety.
Should you find yourself in the water,
avoid panic. Air trapped in clothing can provide buoyancy
as long as you remain still in the water. Swimming
or treading water will greatly increase heat loss and
can shorten survival time by more than 50%.
The major body heat loss areas are
the head, neck, armpits, chest and groin. If you are
not alone, huddle together or in a group facing each
other to maintain body heat.
Proper preparation is essential when
boating on cold water. Make sure your boat and equipment
are in first class condition. Check the weather forecast
before leaving for your event. Always tell someone
where you are going and when you expect to return.
Dress in several layers of light clothing. Next to
a diver's wet suit, wool clothing offers the best protection.
Always wear a personal flotation device (PFD) when
First Aid Considerations For Cold
Treatment for hypothermia depends
on the condition of the person. Mild hypothermia victims
who show only symptoms of shivering and are capable
of rational conversation may only require removal of
wet clothes and replacement with dry clothes or blankets.
In more severe cases where the victim
is semi-conscious, immediate steps must be taken to
begin the rewarming process.
Get the person out of the water and
into a warm environment. Remove the clothing only if
it can be done with a minimum of movement of the victim's
body. Do not massage the extremities.
Lay the semi-conscious person face
up, with the head slightly lowered, unless vomiting
occurs. The head down position allows more blood to
flow to the brain.
If advanced rescue equipment is available
it can be administered by those trained in its use.
Warm humidified oxygen should be administered by face
Immediately attempt to rewarm the
victims body core. If available, place the person in
a bath of hot water at a temperature of 105 to 110
degrees. It is important that the victim's arms and
legs be kept out of the water to prevent "after-drop".
After-drop occurs when the cold blood from the limbs
is forced back into the body resulting in further lowering
of the core temperature. After-drop can be fatal.
If a tub is not available, apply hot,
wet towels or blankets to the victim's head, neck,
chest, groin, and abdomen. Do not warm the arms or
If nothing else is available, a rescuer
may use their own body heat to warm a hypothermia victim.
Never give alcohol to a hypothermia
Some Important Facts To Remember
Most persons recovered in cold water "near" drowning
cases show the typical symptoms of death:
- Cyanotic (blue) skin coloration
- No detectable breathing
- No apparent pulse or heartbeat
- Pupils fully dilated (opened)
These symptoms, it was discovered, did not always mean the victim was dead.
They were, on the other hand, the body's way of increasing its chances of
survival through what scientists call the mammalian diving reflex. This reflex
is most evident in marine mammals such as whales, seals or porpoises. In
the diving reflex, blood is diverted away from the arms and legs to circulate
(at the rate of only 6-8 beats per minute, in some cases) between the heart,
brain and lungs. Marine mammals have developed this ability to the point
where they can remain under water for extended periods of time (over 30 minutes
in some species) without brain or body damage.
Humans experience the diving reflex,
but it is not as pronounced as in other mammals. The
factors which enhance the diving reflex in humans are:
- Water temperature - less than 70
degrees or colder, the more profound the response
and perhaps the more protective to the brain
- Age - the younger the victim,
the more active the reflex
- Facial immersion - the pathways
necessary for stimulating this series of responses
seem to emanate from facial cold water stimulation.
The diving reflex is a protective mechanism for humans in cold water immersions,
but it may confuse the rescuer into thinking the victim is dead. Resuscitative
efforts for these victims should be started immediately utilizing CPR in
accordance with your training.
Remember, numerous children have been
brought up from freezing water after 30 minutes and
been successfully resuscitated.
Expected Survival Time
in Cold Water:
||Exhaustion or Unconsciousness in
||Expected Survival Time
|70–80° F (21–27° C)
||3 hours – indefinitely
|60–70° F (16–21° C)
|50–60° F (10–16° C)
|40–50° F (4–10° C)
|32.5–40° F (0–4° C)
|<32° F (<0° C)
||Under 15 minutes
||Under 15–45 minutes
Permission, December, 2008