|
Cold
weather poses a variety of health risks.
Long term exposure to stale air in tightly insulated buildings
exposes us to all sorts of bacteria and viruses that assault our system.
Extremely dry air causes our skin to crack and on damp days every
old injury aches and throbs. When
the temperature falls below 70 degrees, a medical condition called
hypothermia can start to be a real problem, and it is an insidious
creeping killer.
Hypothermia
can happen on a 70° degrees F. day.
Windy and wet conditions and the exposure to these conditions
increase the chances of getting hypothermia.
In colder conditions the onset can be very sudden, such as an
accidental immersion in cold water.
Dangerous situations where you could get hypothermia include:
-
You
go hiking on a fall afternoon.
It is in the mid 60-ies when it gets cloudy.
An unexpected rain shower passes over with a cold driving
rain, gusty winds, and you have no rain equipment.
-
You
are hiking on a 70° degrees F. day and you are crossing a log that
spans an icy mountain river. You
slip and fall in getting completely wet, and soaking all of your
gear, it is late afternoon and the sun is going down, putting a
chill in the air.
-
Your
paddling down your favorite run on an early summer day.
The river is fed by snowmelt and is very cold. Your rig capsizes and you are plunged into the 45° degrees
F. river and swept by the current for almost five minutes before you
struggle to the shore.
-
You’re
out winter camping. You
are well equipped for the experience and well dressed.
The air is bitterly cold and there is an extreme wind.
You start to feel sore and you start to shiver.
What
is interesting about these four scenarios is only the last one seems
plausible. The fact of the
matter is anyone can get hypothermia even on a sunny slightly cool day.
The very young, the very old, people with metabolic disorders,
people with Parkinson's disease, severe arthritis, who have had a stroke
and people on certain medications are at higher risk of getting this
life threatening condition. Everyone
in their lifetime has experienced being cold and feeling a chill.
We get goose bumps and our teeth chatter, our limbs ache and we
feel a little sleepy. Most
of the time a little jumping in place and a warm drink is all it takes
to get warmed up. Hypothermia is more, and can be serious trouble.
Hypothermia
is a sudden and profound cooling of the temperature in the core of your
body to below 96° degrees F (35.5° degrees C.).
The core for this point of discussion is your torso and your head
where your vital organs are located.
Although this 2-1/2° degree F. drop from a healthy normal 98.6°
degrees F. seems slight, it can have a crippling effect to the body.
Continued cooling can result in an irregular heartbeat that can
lead to death.
We
lose heat a number of ways through our body.
We can lose heat through radiation; most of this heat loss almost
half is through our head. We lose body heat through conduction; this is why we sweat
when we are hot as the heat is carried off in the moisture that
evaporates off of our body. Being
immersed in cold water and then getting out can have a very profound
conduction effect. Convection
can cool us down, that is simply air moving across our body by the wind
or through movement like downhill skiing.
We lose body heat in extreme cold through breathing.
Dry frigid air is breathed in, warmed to body temperature in our
lungs and then exhaled. Wearing
a hat, staying dry and wearing a facemask in extreme cold are all three
very simple steps to preventing hypothermia when outdoors.
Your
brain through a series of complex reactions controls your body
temperature. In the
simplest form as your body cools unexpectedly your brain sends a signal
for you to shiver. Shivering
is small involuntary muscle contractions where your body is attempting
to produce additional heat by creating friction between your muscle
cells. Your body also restricts the blood flow to your extremities,
your hands, and your feet in an attempt to stem heat loss. Shivering, stiff hands, sore feet are all normal parts of
being cold. These are all
signs of impending hypothermia.
|
Canoe
