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 foodssuch as carbohydrates.
Signs of Hypothermia:
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.
Treatment of Hypothermia:
Hypothermia can develop into a medical emergency. The person must
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.
· 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.
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
· 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.