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Clothing & Heat
Loss
By
David Cronenwett
As autumn rolls around,
backcountry hunters begin looking forward to our journeys
into the mountains. We should take care to prepare
ourselves for unforeseen situations involving rapid
changes in the weather, since fall can and frequently
does, morph into winter and back again from day to day.
The biggest problem that
autumn and early winter poses to people is hypothermia,
which is the insidious and potentially deadly lowering of
the body's core temperature. Ironically, hypothermia is
less likely to be a problem in winter-proper because most
people dress warmly enough to expect it. It is more of
an issue during the other three seasons.
Still, a high-stress survival
scenario, one which may find you having to get through a
night or two in frigid cold without a sleeping bag, could
easily push your body into a precariously cold state.
The body loses heat via convection (wind action drawing
heat away), conduction (direct contact with a cold
object), radiation (an un-insulated body in a cold
environment) and evaporation (moist skin conducts heat
away from the body 240 times faster than dry skin). A
simple test for the early signs of hypothermic incapacity
is to touch the thumb to the little finger. If there is
any difficulty whatsoever, you must either exorcise
vigorously or immediately light a fire, the latter being
more desirable. If you are alone, you may quickly become
unable to revive yourself beyond this point of
early-stage hypothermia.
Any of the cold-related
maladies can make fire making difficult or impossible.
Be sure to read the Jack London classic, To Build A
Fire, then try this simple experiment: with a fire
already going, take off your gloves and allow your hands
to become thoroughly numb. Next, try to make a
substantial fire inside of five to ten minutes. If you
succeed, consider yourself lucky. If you fail or give
up, run back to your other fire and remind yourself to
never let your hands deteriorate to
such a state!
Dehydration is a common and
debilitating condition to the recreationist regardless of
the season. All bodily functions including the
thermoregulation system, rely on adequate water reserves.
You will become much colder if you do not drink enough
water to always urinate clear liquid. You may also
develop gnawing headaches, digestion problems and become
lethargic. None of these symptoms are conducive to
making it through a cold weather survival situation. The
body's thirst mechanism should not be used to gauge your
hydration. It is best to drink hot tea or water
throughout the day, which is why a pot of some kind is an
absolutely integral part of the winter survival kit.
The importance of clothing in
survival scenarios and indeed, for all outdoor pursuits,
must never be underestimated. Clothes insulate us from
cold and protect us from rain, snow and abrasion. People
who otherwise would have perished in the wilderness have
been known to squeak by because they were adequately
dressed. In cold conditions especially, you must
wear or carry enough clothing for the worst conditions to
be expected.
The layering system, one that
emphasizes several thin layers over fewer heavy ones, is
well known by most people. However, in the past twenty
years or so, the clothing material of choice, namely
polypropylene fleece and other synthetic fabrics, has
supplanted the traditional option of wool. The reason
for this is almost exclusively fashion and advertising
related, since these products are simply not withstanding
the test of time. Recently however, more people are
rediscovering the amazing qualities of wool and more
companies are manufacturing excellent, high-performance
products.
First, wool is a natural,
renewable fiber that can be sustainable produced and will
eventually biodegrade. Compare this to the petroleum
intensive nature of fleece products that will last for
centuries in the landfill. In my opinion, most synthetic
outdoor garments are vastly inferior to their traditional
wool or cotton counterparts. When working and living
around open fires and woodstoves, having a wardrobe of
plastic clothes can be simply dangerous. I have seen
expensive parkas and fleece pullovers riddled with "spark
holes", and witnessed the gruesome melting and outright
combustion of gloves, hats, pants and other items made of
similar materials.
Wool and canvas are much less
flammable and are easier to repair when damaged. Wool
lacks the disturbing quality of some synthetics to hold
on to body odor forever, no matter how many times you
launder them. Companies like Ibex have a line of
excellent, durable and non-itchy garments for a wide
range of outdoor pursuits including mountaineering and
backpacking. Their Merino wool long underwear line is
absolutely to die for.
The so-called
waterproof-breathable fabrics that comprise the bulk of
raingear today will never live up to its own
advertising. Hard, sustained use in the wilderness, as
opposed to weekend outings will destroy these products in
short order. Though they may technically breathe, they
cannot do enough of it to prevent moisture buildup (from
perspiration) and eventual saturation of your inner
layers, especially when you are working strenuously. A
good wool coat may keep you as dry or more so than a
Gore-tex parka. If you are interested in staying truly
dry, by impermeable rain gear, seek shelter and wait out
the weather, since physical activity in any
rainwear will soak you from within.
Having said all this, I
recognize that many people use synthetic clothing and
there is a place for it. We would only like to recommend
that individuals who spend a lot of time in the
wilderness to give wool clothing a try, you may be
surprised by the results. Original at: http://wilderness-arts.com/clothingheatloss.html |
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