Hypothermia And Cold Injuries
We expect that hypothermia will be a major concern if the weather is cold and the protesters are not adequately prepared to be exposed to cold for a long time. Quebec City is a chilly and windy area. Remember, most people are outside in the winter for less than 30 minutes at a time. Few are out for more than two hours. Quebec City climate: April: Minimum: -2 Celsius/ 28 Fahrenheit. Maximum: 8 Celsius/ 46 Fahrenheit , snow + rain May: Minimum: 5 Celsius / 41 Fahrenheit. Maximum: 17 Celsius / 63 Fahrenheit. Hypothermia occurs when the body cools down too much because of cold weather or being wet and cool. Risk Factors: Cool , cold, wet, or windy environment. Improper clothing and equipment. Fatigue. Dehydration. Age. Immobility. Poor food intake. No Knowledge of Hypothermia. Alcohol intake, cigarettes. Poor circulation. Not taking hypothermia seriously. |
Prevention of hypothermia & cold injuries:
· Keep well hydrated, drink at least 2-3 liters a day, and eat energy foods
such as carbohydrates.Mild:
Shivering. Can't do complex motor functions with hands
but can still walk and talk. Skin is cool due to vasoconstriction. Hands numb.
If shivering can be stopped voluntarily, it is mild hypothermia. If a person
cannot count backwards from 100, they could be hypothermic.
Moderate Hypothermia: Shivering
not under voluntary control . Loss of fine motor control - particularly in hands
- can't zip up coat - due to restricted peripheral blood flow. Incoordination.
May have: Dazed consciousness. Slurred speech. Violent shivering. Irrational
behaviour - may even undress unaware that s/he is cold. "I don't care attitude"
- flat emotions/affect.
Severe Hypothermia: (Don't let it get this far!): Shivering occurs in waves until shivering finally ceases. Irrational. May be able to maintain posture and appearance of awareness. Progresses to: Person can't walk, curls up into fetal position to conserve heat. Muscle rigidity. Skin is pale. Pupils dilate (become big). Pulse rate decreases. As it progresses, breathing and heart rate decreases. Then the person looks dead, but is still alive.
Hypothermia can develop into a medical emergency. The person must
be re-warmed.
Mild to Moderate Hypothermia
The best way is by the person's
own body heat. Replace wet clothes with dry clothes. Additional layers of dry
clothes & blankets to insulate the person against escaping body heat. Increase
physical activity. Consider: Get out of cold. Add Fuel & Fluids: Carbohydrates
are quick (best in mild hypothermia) & Proteins which gives a slower heat over
a longer time. Fats give off heat slower and longer, but takes more energy &
water to break down fat.
Inefficient ways: Hot drinks.
Feels better than is effective. Careful not to burn mouth/tongue.
Add Heat: External
heat source (warm room).
If outside: body to body contact - get into a sleeping
bag in dry clothing with a warm person in lightweight dry clothing. Heat pads.
Severe Hypothermia
1. Reduce Heat Loss:
Hypothermia wrap: Provide
a shell of total insulation. No matter how cold, the patient can still internally
rewarm themselves more efficiently than any external rewarming. Make sure patient
is dry, with synthetic layer to minimize sweating on skin. Use multiple layers,
foam, etc. to create insulation. Include aluminum "space" blanket to prevent
radiant heat loss.
2. Add Fuel & Fluids:
Warm Sugar Water - With severe hypothermia, stomach shuts
down and wont absorb solid foods. Dilute mixture of warm water w sugar every
15 minutes. Dilute Jello works best since it is part sugar part protein.
Urination: A full bladder
is a place for extra heat loss. You will need to help the person urinate.
3. Add Heat:
Hot water bottles, hot pads, etc. to transfer heat to
major core arteries - neck, armpits, groin, palms of hands. Best to rewarm
the core body this way only - not the arms & legs.
(When person becomes hypothermic, blood is shunted away from arms/legs. If peripheral
vessels open up, cold acidic blood from periphery goes to core - may cause heart
arrhythmias and death.
Frostbite
· Happens only in temperature below freezing.
If tissue freezes, ice crystals form in cells. Distal
areas of body most susceptible: ears, nose, fingers & toes.
· Treatment: Do not rub tissue:
can damage cells from ice crystals. Rewarm gently. If deep frostbite, consider
immersion in warm (not hot) water 25 - 40 minutes. If hot - can burn damaged
skin. Thawing is complete when part is pliable and colour and sensation return.
Once area has rewarmed, there can be considerable pain.
· Wrap affected area in sterile gauze and
protect from movement and further cold. Treat as a tissue injury - consider
hospital if significant tissue damage.
· Once a body part has been rewarmed, it cannot be used
for anything until tissue begins to repair. It
is essential that in not be refrozen - causes more damage. If you cannot guarantee
that the tissue will stay warm, do not rewarm it.
· If person is hypothermic and frostbitten: priority is
treating hypothermia. Do not rewarm frostbitten
areas until core is warm.
Trench Foot
Wet feet loose heat 25x faster than dry. The body uses vasoconstriction to shut down peripheral circulation in foot to prevent heat loss. Skin tissue than can begin to die. Can also cause permanent damage to the circulatory system making person more prone to cold related injuries.
Prevention & Treatment of Trench
foot:
· Keep feet dry. Water-proof
boots. Check feet regularly (if wet from sweating or immersion), stop and dry
feet, put on dry socks, consider plastic bag over dry socks / between wet boots
- but beware of vapor barrier increasing sweat wetting foot.
· Some mountaineers will put antiperspirant with
aluminum hydroxide on feet for week before trip (keep feet from sweating up
to a month).
· Experiment to see if your feet sweat much. If
not, consider vapor barrier. If so, use socks that wick away sweat, and water-proof
boots. · If trench foot sets in, foot is more susceptible to damage by walking
on it.