
     The Silent Killer  
          by  Roger Meyer  
          
Bowhunter Magazine  Feb/Mar 94  

             
Have you ever shivered or found it difficult to talk properly in
cold weather?  Have you ever had problems walking because you
were so cold!  If your answer is yes, you could have been on the
verge of becoming a victim of hypothermia.  If the answer is no,
you have lucky - so far.              
     You might ask, "So what?  How can I get into trouble in
cold weather?  I've been outdoors a lot and have never had any
problems." 
     You can get into trouble three ways: becoming injured and
unable to get help, getting wet in a rain storm or falling into
cold water.  The biggest danger from cold weather is
hypothermia.   
     Hypothermia is the total physical and mental collapse that
occurs when the vital organs of the human body are chilled.  A
victim of hypothermia will die unless someone helps them.   
     Hunters are usually able to cope better with winter
conditions than the average person.  They're familiar with the
outdoors and wear warm clothing including gloves, boots and a
hat.  They may even carry matches and snack food.                 
     The weather doesn't have to be very cold to cause a
problem.  Most hypothermia cases occur between 32 and 5O
degrees.  Few outdoorsmen believe that these mild temperatures
can cause trouble.  Don't think that hypothermia is a joke; it
can kill you.   
     Body temperature starts to drop when body heat is lost
faster than it's replaced.  When the temperature of the vital
organs, often called the body core temperature, drops to 97
degrees shivering begins and becomes more violent as the core
temperature continues to drop.  Shivering consumes a lot of
energy, about the same amount you would use to saw wood.
Shivering delays hypothermia but you must do something to reduce
the heat loss from your body before your energy reserves are
fuIly depleted.      
     Keep in mind that shivering is a warning that your body's
core temperature has dropped and you are on the way to becoming
a victim of hypothermia.  You must do something quickly to
prevent your body temperature from dropping further.  Your life
is in danger!
     At about 92 degrees core temperature, shivering stops and 
the muscles become rigid.  Victims are usually incapable of
helping themselves at this point and need assistance to survive.  
A victim is irrational and can't speak at this stage.
     As the body temperature drops further, you enter a stupor 
and then loseconsciousness.  When body temperature drops to this
point, simple external warming won't correct the problem because
the core temperature will continue to drop for some time even
after external heat is applied.  Then, professional medical help
and equipment is required for the victim to survive.  One method
used is to carefully have the victim breathe hot air that
quickly heats the heart and lungs.  At a body temperature of
about 78 degrees, death occurs.  
     People have become victims of hypothermia in a matter of 
minutes.  Incapacitating, violent shivering can begin immediately 
after exposure to extreme cold.  For example, a sudden problem 
occurs after falling into water.  If this happens, strip off
your clothes and wring out as much water as possible before
putting them on again.  Then find shelter quickly.  
     Wet clothing greatly increases heat loss because the
insulating qualities of most clothing is lost when wet.  Wet 
clothing causes problems and you don't have to fall in water to 
get your clothes wet.  Rain or perspiration will do the same
thing, only slower.  
     Hypothermia is easy to recognize in someone else.  It's 
difficult to recognize in yourself because hypothermia quickly 
impairs mental capabilities and makes its victim lethargic.  A
cold body temperature strips you of judgement and reasoning power.  
You don't realize this is happening.  Victims quickly lose the 
mental and physical capability to help themselves.  A person
alone must be alert of this danger.  
     There are four ways to cope with hypothermia: get out of  
the cold to warm shelter, reduce heat loss by using more clothing 
or other covering, exercise to increase heat production or eat 
food to increase your internal heat generation.  
     The nearest warm place for most people is often a sheltered 
spot with a fire, but this is not considered by most of us
because building a fire to get warm seems like a lot of trouble - 
or maybe building a fire is admitting you have a problem.  Admit 
you have a problem and build that fire. It can save your life.
     The site you choose for a shelter must be out of the wind.  
Even a slight breeze increases the probability of hypothermia 
because it lowers the effective ambient temperature.
     The next best way to cope with hypothermia is extra 
clothing or other covering.  Have more clothing than you think 
you need and carry a space blanket.  A space blanket costs only 
a few dollars and occupies little room in your pocket or pack.  
A space blanket is aluminum foil supported on both sides by
flexible transparent layers.  The foil reflects your body heat
back toward you reducing heat loss.
     Perhaps the most essential item of clothing is a
headcovering - a hat or a parka on a Jacket.  About 25 percent
of the radiated body heat is dissipated from the head and neck.  
     Exercise will keep you warm and prevent hypothermia
temporarily.  However, exercise of any kind drains your energy
reserves and exercise vigorous enough to keep you warm will
eventually leave you exhausted and unable to continue with
physical activity.  
     Exercise also increases heat loss.  When a person starts to
become chilled the body restricts blood flow to the
extremetuies, which then reduces heat loss.  With exercise,
normal blood flow is restored to the hands and feet.  This
increases heat loss, which is what caused your problem in the
first place.  Exercise is a temporary way to delay hypothermia
until you can find another solution.              
     Eating food helps prevent hypothermia.  Digestion generates
internal heat and the food provides energy. Eating cold food
won't belp you if your core temperatitre has dropped to 94
degrees because your body starts to shut down and digestion
doesn't take place.
     Carry suitable food with you and eat some at the first sign
of a problem.  Hot beverages are great to help keep you warm and
it's a good idea to bring some along in a Thermos.  Otherwise,
you can obtain bot water by melting snow.  But, it's a slow
process to melt snow.  It helps to put only a small amount of
snow in the pot until you get a layer of water, then add more
snow.  Don't ever eat snow or ice for your thirst in this
situation.  It takes a lot of energy for your body to melt the
snow and then heat it to body temperature.
     Carry special items with you in cool weather.  The items
should include a space blanket, candles or firestarters,
matches, a spoon, instant hot beverage mixes, high energy foods,
a whistle and a plastic trash bag.  Cut a hole in tbe trasb bag 
for your head and you have an emergency shelter or instant
windbreak.  Everything can be carried in a belt pouch or in a
pocket.  
     Carry a Sierra cup or tin can to heat the water or food.
A Sierra cup is a small steel container with a wire handle
that's a combination pot and cup.  A small metal box, such as a
Band-Aid box, could carry most of the above items and could then
be used as a cup or cooking pot.  
     The candles or firestarter make it easier to build a fire
because you don't want to struggle to start a fire if you have a
problem.  The whistle can be heard by a search party over a
longer distance than the human voice and it's much easier than 
shouting.  
     Granola bars, hard candy, nuts, powdered soups and canned
sardines travel well in your pockets for either snacks or
emergencies.
     When people are in an unusual situation, they often react
and do something - anything - and they feel they must do it
quickly.  The first reaction is hasty and often a mistake.  If
your unusual situation involves a possibility of hypothermia, a
hasty move could be fatal.                      
     Remember, an unprepared person can lose his or her life.
But with just a few items in your pocket and a little knowledge
in mind, you can be stranded outdoors in reasonable comfort and
safety - and - survive.    




