Outdoor safety topic cold injuries
Source:
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Parklands XC Ski Club, Tour Leader Program.
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REMEMBER - THE BEST DEFENSE IS:
- CARDIOVASCULAR FITNESS
- GOOD NUTRITION
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SENSIBLE CLOTHING
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What it is
Frostbite is freezing of specific parts of the body.
What causes it
When exposed to cold, the body protects the inner core by constricting surface blood
vessels. This results in decreased blood flow and heat to surface skin.
Where it occurs
Fingers and toes are most susceptible to frostbite but any part of the body exposed
to cold air can be affected. Once a part has been frozen it is more liable to cold
injuries on subsequent occasions.
How to recognize it
Frostbite is progressive:
- Frostnip - The skin turns white and becomes numb;
- Superficial Frostbite - The tissue beneath the surface feels soft and resilient;
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Deep Frostbite
- The tissue beneath the surface feels hard and wooden.
What to do when it occurs
Frostnip is the only form of frostbite you can treat on the spot:
- act now - hold hands over face and warm with breath;
- re-warm fingers under armpits or between thighs;
- apply firm steady pressure, do not rub;
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if toes are affected, remove boots and hold feet between hands or place on a friend's
stomach (keep foot covered with layers of clothing); or
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if feeling fails to return, or if skin remains white assume you have a case of superficial
frostbite.
Treating Frostbite
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DO NOT ATTEMPT TO REWARM. Get to a doctor or hospital as soon as possible.
The victim can walk or ski on frozen feet without further damage;
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if frozen feet are re-warmed in the field the person immediately becomes a stretcher
case. You have an emergency on your hands requiring outside help and a possible
overnight survival situation. Should the affected part become frozen again while
waiting for rescue, further damage will be caused to the tissue;
- NEVER rub the affected part with your hand or with snow; and
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NEVER try to re-warm in front of a fire.
How to prevent it
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To resist frostbite your body needs to be healthy. Do not venture out in very cold
weather if you are feeling tired or suffering from a cold or the flu;
- Avoid tight-fitting clothes. Use the layer principle;
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Tight boots constrict circulation and create cold spots. Laces should be loosely
done up;
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In windy conditions, put on windproof clothing. Put on overmitts, overboots, or
oversocks before you get too cold. Protect your face with a balaclava or scarf;
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Do not touch cold metal with bare fingers (i.e. cameras, metal canteens, ski bindings,
snow shovel.);
- At lunch break insulate your feet by keeping your skis or snowshoes on;
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Carefully watch your companions for signs of frostnip appearing on the face. Cheeks
and chin are the usual places affected;
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If your feet become numb, wiggle your toes vigorously. If this doesn't work STOP
AT ONCE, remove boots and re-warm. Even though the laces may be frozen and hard
to undo, persevere;
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Forget about smoking on the trail. Nicotine constricts surface blood vessels, predisposing
the smoker to frostbite. The temperature of fingers and toes can drop as much as
5 degrees Celsius;
- Do not overheat. Perspiration leads to more cooling; and
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Stay dry, including your feet.
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What it is
Hypothermia is a disease that can develop quickly and kill you. It is a condition
of the body that occurs when the inner-core temperature drops to a level where the
vital organs no longer function effectively.
What causes it
Hypothermia develops when your body loses more heat than it can produce. It is caused
by exposure to cold, wet or windy conditions and fatigue. The greatest single factor
to bring on hypothermia is improper clothing.
Where it occurs
Hypothermia can occur anywhere that the temperature is low enough to reduce the
inner-core temperature of the body to the danger level. It occurs most frequently
in rugged mountain terrain where a person on foot can pass from a calm and sunny
valley to a wind and rain-lashed mountain ridge in a short time period. Most hypothermia
accidents occur in outdoor temperatures between -1 and 10 degrees Celsius.
How to recognize it
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In the early stages, hypothermia may be confused with fatigue or intoxication. It
is important to remember that the victim is unable to recognize his condition. He
may insist that he is fine. Children and adolescents are at particular risk; they
have less endurance than adults, tire more easily and are unable to pace themselves.
Leaders of youth groups must be constantly on the lookout for early symptoms. Treatment
must be prompt;
- The victim feels chilled and begins to shiver uncontrollably;
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As surface blood vessels contract in the body's first defense mechanism, hands become
stiff and fumbling;
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The person is unable to think clearly. He cannot make decisions, his speech may
be slurred, and he becomes unresponsive to people around him. Often he acts in a
totally different manner to normal;
- He stumbles frequently, cannot pick himself up. Shivering may stop at this point;
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The victim has an overwhelming urge to sleep. He lapses into a stupor and finally
unconsciousness;
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Death is caused by heart failure.
What to do when it occurs
- Death may occur within one hour of the onset of hypothermia.
- ACT QUICKLY: PREVENT FURTHER HEAT LOSS.
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In the early stages, stop and put on more clothing. Nibble high energy foods. Transfer
body heat from other members of the group. Build a fire. Although the victim may
appear fully recovered and wish to continue with the tour, turn back.
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Treatment in the later stages of hypothermia is much more difficult. Because the
person has lost the ability to produce heat, outside heat must be added:
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Move the victim out of the wind into the shelter of trees or a boulder. If you have
a tent, put it up quickly and get him inside.
- Make sure the victim is insulated from ground snow by packs, boughs, etc.
- Remove any wet clothing and replace with dry.
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Put the victim in a sleeping bag if you have one. Get another person to strip to
their underclothes and transfer heat by body contact.
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If you do not have a sleeping bag, other members of the party should huddle around
the victim in an attempt to transfer warmth. Get a good fire going.
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If the victim is conscious give hot sweet drinks like Jell-O or easily digested
carbohydrate foods like candies, sugar lumps and dextrose.
- If semi-conscious, try to keep the victim awake at all costs. Give hot drinks.
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Although the victim is unconscious and may even appear to be dead, redouble your
efforts to transfer heat. Well wrapped hot rocks from the fire or metal canteens
filled with hot water placed inside the sleeping bag will help.
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Two strong tourers must go for outside help. The rest of the party should make every
effort not to become hypothermic themselves. Keep busy. Build a fire and emergency
shelters in case the wait for help becomes a long one.
How to prevent hypothermia
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Eat a good breakfast before setting out on the tour. Fats and proteins will supply
a constant source of heat throughout the day. During the tour, stop several times
to eat high energy foods like chocolate bars, gorp, fruit cake;
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Keep heat in by dressing sensibly. Use the layer principle and include at least
one layer of wool. Be particularly careful in windy conditions. Make sure that your
outer layer of clothing is windproof and that your extremities are given extra protection;
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Be fit. Fatigue is often associated with hypothermia. Good technique (skiing) will
reduce fatigue;
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Breathing through a scarf or the high collar of a sweater can reduce loss of heat
by respiration. In this way, air can be re-warmed and pre-humidified before going
into the lungs;
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Take care crossing lakes or rivers. Be wary of thin ice where rivers enter or leave
lakes. Cross rivers at their widest points where the current is slowest;
- Prevent dehydration by the intake of liquids;
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The body temperature can drop considerably during a lunch break. As soon as you
stop, put on your down jacket even though you may be hot from exercise. Conserve
heat. During very cold weather, several short five minute breaks for food are better
than one long lunch break;
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Don't drink alcohol if you are tired and haven't eaten for some time. Alcohol blocks
the release of glucose into the bloodstream and causes a drastic drop in core body
temperature; and
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If you cannot seem to keep warm on a tour, turn back. You may save your life.
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What causes it
Snow blindness is the result of the eyes being exposed to too much solar radiation.
What to do when it occurs
Apply cold compresses, retreat to a dark environment; cover both eyes to prevent
eyeball motion. Pontocaine will temporarily allay the symptoms but it will not treat
the condition.
How to prevent snow blindness
Wear good sunglasses.
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What it is
A burn like irritation.
What to do when it occurs
Apply a grease or oil based ointment.
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What it is
A first or second degree burn caused by exposure to the suns rays.
How to prevent it
Wear adequate clothing; apply opaque ointments or lotions containing aminobenzoic
acid (PABA).
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What it is
An irritation of the eardrum caused by the wind.
How to prevent it
Place a plug of cotton or soft tissue in the outer ear canal.
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What causes it
Cold dry weather; excessive washing with soap.
What to do when it occurs
Apply animal or vegetable oils.
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What causes it
Even in a cold environment the body loses two to five or more quarts of moisture
per day. Dehydration makes the blood more viscous which lessens cardiac efficiency
and decreases the body's ability to carry out its functions.
How to recognize it
Irritability, deep orange or brown urine, economy of movement, headaches, etc.
Treatment/Prevention
Adequate fluid intake.
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What causes it
Repeated exposure of bare skin to temperatures between 0 and 10 degrees C.
How to recognize it
The skin becomes red, rough, and itchy, but there is not loss of tissue.
Treatment
Apply a soothing ointment. Prevent further exposure.
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What causes it
Heavy breathing in a very cold environment.
How to recognize it
Breathing discomfort, coughing, asthmatic type reactions, and coughing up blood.
Treatment/Prevention
Pre-warm the air with hoods, masks, or re-breathing tunnels, etc. Humidify the living
environment. Eliminate smoking.
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What causes it
Exposure to wet conditions, usually above freezing, for hours or days. This can
occur with skiers using ski boots made of non-breathable plastic materials, or if
they are using a Vapour Barrier system. Wet socks in leather boots for extended
periods of time can produce the same effect. Tissue damage may occur with no more
moisture than condensed sweat inside plastic or rubberized boots.
How to recognize it
Cold, swollen, blanched feet that feel heavy and numb. There is a sensation of "walking
on cotton wool". This stage is rapidly succeeded by one of hyperemia in which the
feet are hot and red. This may persist for days or weeks. Swelling and pain may
be severe, and blisters may form, leading even to gangrene. At this stage it may
be difficult to differentiate from frostbite, but the damage to nerves and muscles
may be longer lasting, and may even be permanent.
Treatment
Dry the feet, add warmth, and restore circulation.
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