CAP Ground Team-

Prevent & Treat Cold Weather Injuries

Task O-0004Revision January 2012

Prevent & Treat Cold Weather Injuries

(Task O-0004)Reference:

Ground & Urban Direction Finding Team Tasks (24 May 2004)Ground Team Member & Leader Reference Text (Revised Arpil 2003)

Objectives

Take steps to prevent cold weather injuries and recognize and treat those that do occur

All too often we focus on recognizing andtreating cold weather injuries.

However, the more important issue is …

PREVENTIONRemember: Cold Weather Injuries are

preventable!

• Cold injuries are a result of unstopped cooling of body parts of the whole body.

• To prevent cold weather injuries, it is essential to remain warm and dry.

• If the skin is wet, it will lose heat twenty times faster than if it is dry.

• People who have had cold weather injuries in the past are more likely to have them again.

• It is important to identify all personnel in your team who have a history of cold weather injuries, and watch them carefully.

COLD WEATHER CLOTHING

Cold weather clothing systems are designed to change with your needs. Cold weather clothing protection is based on principles of insulation, layering, and ventilation. By understanding these principles, you will be able to vary your clothing to regulate protection and stay comfortable

Increased Effort on Your Body

• Because cold weather clothing is typically heavy and cumbersome, it greatly increases the energy required for physical activity.

• The increased effort can result in overheating and sweating, especially during hard work, and can contribute to fatigue.

• Perspiration buildup should be minimized by opening clothing and removing layers during heavy work and scheduling frequent short rest breaks.

• Eat and drink more when it's cold out to keep your body fueled. More fuel = more energy and heat.

Vasoconstriction&

Shivering

• Humans protect themselves from cold primarily by avoiding or reducing cold exposure using clothing and shelter.

• When this protection proves inadequate the body's internal mechanisms to defend its temperature of vasoconstriction and shivering takeover.

• Vasoconstriction and Shivering will be explained further in the next slide.

Vasoconstriction

• The body has a natural defense mechanism to shift blood from the extremities to the major organs in your torso area in order to keep itself alive; which in turn, causes the extremities to get cold first.

• When the body starts to loose more heat than it can easily generate, it will allow your extremities (fingers, toes, ears, nose, and cheeks) to start get cooler.

• This happens by Vasoconstriction, which is the tightening of blood vessels in the skin when it is exposed to cold. While blood will still flow to your extremities, it is at a much lower rate.

• The reduced skin blood flow conserves body heat, but can lead to discomfort, numbness, loss of dexterity in hands and fingers, and eventually cold injuries.

Shivering

• Shivering is your body’s attempt to generate heat through muscle activity. It increases heat production, which helps to offset the heat being lost.

• Internal heat production is also increased by physical activity, and the more vigorous the activity, the greater the heat production. In fact, heat production during intense exercise or strenuous work is usually sufficient to completely compensate for heat loss, even when it is extremely cold. However, high intensity exercise and hard physical work are fatiguing, can cause sweating, and cannot be sustained indefinitely.

• However, most ground team activities and tasks are less vigorous than high-intensity exercise, so internal heat production will probably not be adequate to offset heat loss.

Minimizing Cold Effects

• Susceptibility to cold injuries can be minimized by maintaining proper hydration and nutrition, avoiding alcohol, caffeine, and nicotine, minimizing periods of inactivity in cold conditions.

• Minimize the risk of cold injuries at base camp and field observation points by placing pads, sleeping bags, tree boughs, etc. Inside these positions to allow occupants to insulate themselves from the ground or snow.

• High levels of physical fitness are also beneficial for personnel participating in cold-weather operations.

Cold WeatherAcclimatizing

• Humans do not acclimatize to cold weather nearly as well as they can acclimatize to hot weather, although repeated cold exposure does produce what is referred to as habituation.

• Proper training before sending personnel into cold weather regions is more important for prevention of cold injuries than repeatedly being exposed to cold temperatures.

• Following habituation shivering is much less vigorous. This is advantageous because shivering is inefficient, and most of the heat produced is lost. Also, shivering can interfere with sleep, causing fatigue.

• With habituation to repeated cold exposure, humans adjust mentally and emotionally. Training outdoors in cold weather before deployment will help build confidence in team member's ability to physically, mentally, and emotionally contend with the stress of cold weather conditions.

• Cover all extremities by using gloves, wool socks, and a knits hat or hood over your ears

• Use the layer principle -- Several loose layers of clothing keep a person warmer than one bulky item of clothing.

• Multiple layers of clothing trap warm air pockets, which help maintain a uniform body temperature

• As you exert yourself and begin heating up, remove layers as needed. Put them back on as you cool down.

• Layers can include underwear, socks, thermal underwear, sweater or sweatshirt, uniform, field jacket liner, field jacket, knit hat, glove liners and gloves

• Use the buddy system and check each other for proper dress (gloves; loose, layered clothing) as well a for signs of cold weather injuries.

Cold Weather Clothing Considerations

• Choose clothing that will trap air pockets yet allow moisture to pass through.

• Wool, polypropyleneand Gore-Tex are good fabric choices that remain warm when wet. Rubber or vinyl coats are extremely bad, as they hold the body’s moisture in.

• Avoid getting wet, especially your feet. Stay out of streams and muddy places.

• Avoid overexertion that could cause you to sweat.

Cold Weather Clothing Considerations

(continued)

• Change clothing when it is wet or dirty, especially socks.

• Never allow a team member to unnecessarily wear wet clothing.

• Change socks regularly• Don’t forget: Identify and closely monitor

personnel who have previously suffered a cold-weather injury, as they are more susceptible.

Cold Weather Clothing Considerations

(continued)

Just say NO to COTTON

• Instead, go with synthetics.

• Cotton absorbs moisture and dries slowly, which will increase your chances for hypothermia.

• Experienced rescuers call jeans and T-shirts the hypothermia uniform for this reason.

• Additionally, cotton socks become very abrasive when moist, causing additional friction which can lead to hot spots or eventually blisters.

Dressing for Cold Weather

• The best way to dress for winter is to wear layers. This gives you flexibility to add or remove layers, depending on the weather and your activity.

• If you tend to get cold very easily, dress with more layers.

• In general there are three main layers:

WICKING (1st/Base Layer)

INSULATING (2nd/Middle Layer)

PROTECTION (3rd/Outer Layer)

Wicking Layer(also known as the 1st or Base

Layer)

• This is the layer worn next to your skin, usually consisting of lightweight long underwear.

• This layer is designed to wick excess moisture away from your body.

• Look for thermal underwear made of a synthetic (usually polyester) fiber that has "wicking" power. This means the fibers will wick (move) moisture away from your skin and pass it through the fabric so it will evaporate. This keeps you warm, dry and comfortable.

• Silk is also a good, natural fabric that has wicking abilities. Even though it's cold, you will sweat (especially if you are being active).

• Note: If you know you sweat a lot, bring an extra wicking layer with you on your next outdoor adventure. Change this layer midway through your workout.

• Remember: Cotton is NOT a good choice as it traps moisture instead of wicking it away.

• This middle layer is heavier than the first and includes sweaters, sweatshirts, vests and pullovers.

• The purpose of this layer is to keep you warm by trapping air close to your body.

• Popular insulation materials include: ─ Fleece, a synthetic material which maintains its

insulating ability even when wet and spreads the moisture out so it dries quickly.

─ Wool, which naturally wicks away moisture.

• A nice, mid-weight wool or fleece sweater, expedition weight capilene or polypropylene pullover, or fleece vest works well.

• In colder climates, or if you’re not burning a lot of calories and sweating, wear a heavier wool or fleece jacket.

Insulating Layer(also known as the 2nd or Middle

Layer)

• The exterior layer, generally a shell and pants, serves as your guard against wind, rain and the elements of winter.

• It should repel water and block the wind, while also letting perspiration evaporate. Most genuine winter shells and pants are made waterproof and breathable to some extent by using tightly woven fabrics teamed with a coating or laminate. This keeps moisture on the outside but allows perspiration to escape, keeping you dry and comfortable.

• Avoid damaging or scratching this layer. These materials often loose their protective qualities when scratched or worn away.

Protection Layer(also known as the 3rd or Outter

Layer)

Additional Clothing Considerations

• Headwear: Up to 60 percent of your body's heat can escape

from an uncovered head, so wearing a hat, cap, or headband is essential when it's cold.

• Fleece Neck Gaiter or Face Mask Is a must on cold days.

• Sunglasses and Goggles: Sunglasses do much more than make you look

cool. They also protect your eyes from damaging solar radiation. Snow, or any other reflective surface, makes ultraviolet (UV) rays stronger, while increased altitude also magnifies the danger. On flat-light days or when it's snowing, goggles are vital. They protect your eyes and special lens colors increase the contrast so you can properly discern terrain features.

Additional Clothing Considerations

(continued)

• Gloves and Mittens: Look for gloves and mittens that use

waterproof, breathable fabrics. Mittens, in general, are warmer than gloves, but offer you less dexterity. Consider the type of activity you'll be doing. In addition, you might want to consider liners.

• Socks: Socks are made from a variety of materials,

including polyester, silk, wool and nylon. Some socks have wicking properties similar to long underwear, meaning your feet will stay dry and comfortable.

• Feet, hands and exposed skin must be kept dry.

• Feet are particularly vulnerable and extra foot care is required for cold-weather operations.

• Feet should be washed, dried, and dusted with a dry, antifungal powder daily. Socks must be changed whenever they become wet from exposure to rain or snow, or from excess sweat. This may require changing into dry socks at least 2-3 times daily. Extra socks can be air dried and then carried under BDU's to warm.

CLOTHING GUIDELINES “COLD”

C: Clean clothes: Dirt and grease reduce the insulating

properties of clothing

O: Avoid Overheating (avoid): Don't overdress…. It causes excess

perspiration; which causes dampness and reduces insulating properties.

L: Wear Loose & Layered clothing: Tight clothing restricts circulation, restricts movement, and lessens volume of trapped air

D: Keep clothing Dry:Remember that dampness lessens the

insulating properties of clothing

COLD WEATHER INJURIES:

SYMPTOMS & TREATMENT

•When prevention fails it is critical that everyone be able to recognize and treat cold-weather injuries.

•The main cold weather injuries of concern to Ground Teams are:

― HYPOTHERMIA― FROSTBITE

HYPOTHERMIA

The “umbles”-stumbles, mumbles,

fumbles, and grumbles

Hypothermia occurs gradually and is usually the result of wet clothing, a cold environment or

improper clothing.

Often people aren’t aware that they need helpor medical attention.

According to the Mayo Clinic, nearly 700 people in the United States die each year from

hypothermia.

HYPOTHERMIA

•Hypothermia is the systemic cooling of the entire body. The body’s core temperature falls below average and starts affecting the body’s circulatory system.

•Severe body heat loss-body temp falls below 95oF

•Hypothermia is a life-threatening situation caused by prolonged cold exposure and body-heat loss.

•The air temperature does not have to be below freezing for people to develop hypothermia, especially if the person is wet or if it is windy.

HYPOTHERMIA(continued)

• Hypothermia occurs when:─ Conditions are windy, clothing is wet, and/or

the individual is inactive─ Extended water exposure or immersion

• 1 hour or less when water temp is below 45oF

• Prolonged exposure in slightly cool water (e.g. 60oF)

• Thunderstorms, hail, rain and accompanying winds

• Hypothermia has two stages that require different treatments:─ Early Stage of Hypothermia─ Later Stage of Hypothermia

Early Stage Hypothermia

Symptoms• Uncontrollab

le shivering

• Numbness

Treatment• Keep the patient

warm and dry

• Remove wet clothing

• Warm the central body before the extremities to keep blood from flowing away from the major organs. This can be done using a Hypothermia Wrap (shown in next slide)

Hypothermia Wrap“The Human Burrito”

1. Lay a plastic tarp or emergency/space blanket on the ground

2. Place blankets and/or sleeping bag on top

3. Add three more sleeping bags and place the victim in side the middle one; dressed in dry clothes and heart or scarf on head with heating pads at the armpits, groin and neck.

4. Wrap the tarp or space blanket around the sleeping bags, burrito style, to protect from weather and retain heat.

Later Stage Hypothermia

Symptoms• Shivering stops • Drowsiness• Inability to perform simple

actions (loss of coordination)

• Slow pulse and breathing rate

• Failing eyesight and a “glassy stare”

• Unconsciousness

Treatment• All treatment steps

for early hypothermia

• Handle the patient gently and place in a head-down position

• Transport the patient to medical care immediately

• Handle the patient gently and place in a head-down position

• Transport the patient to medical care immediately

Positions to Reduce Body Heat Loss in

Water

Sharing body heat with others is one of the surest ways to extend your life while waiting for rescue. Keep small children or others threatened in the middle of the huddle for maximum benefit.

When by yourself use the H.E.L.P method: “Heat Escape Lesening Position”. Cross your arms and legs, and pull your knees up as close to your chest as possible. This huddles your body parts across you’re a domen, which is the body’s greatest radiator of core body heat.

IMMERSION FOOT

(TRENCH FOOT)

• Immersion Foot (Trench Foot) is caused by prolonged exposure of feet to wet conditions at temperatures between 32 and 50 degrees Fahrenheit.

• Inactivity and damp socks and boots (or tightly laced boots that impair circulation) speed the onset and severity.

IMMERSION FOOTSYMPTOMS

• Cold feet, which may become numb; feet may later feel hot with shooting pain. There may also be swelling, redness, and bleeding.

• Walking becomes challenging

IMMERSION FOOTTREATMENT

• Re-warm feet by exposing them to warm air, evacuate victim for medical attention.

• DO NOT break blisters, apply lotions, massage, rub, moisten or expose affected area to intense heat.

• Clean and wrap loosely

• Elevate to reduce swelling

• DO NOT allow to walk on injury

DEHYDRATION

Dehydration, which is the depletion of body fluids, is just as common in cold weather as it is in hot.

People don’t feel as thirst when the weather is cold and therefore they don’t drink as much, which leads to dehydration.

SYMPTOMS & FIRST AID

Symptoms:•Dry lips & tongue, nausea, bright or dark colored urine, dizziness, weakness, headaches, and blurred vision.•You can also check skin turgor, which is the skin’s ability to change shape and return to normal (elasticity)…… Skin turgo will be explained in the next slide.

First Aid:•Always drink plenty of fluids, especially during and after extended physical activity.

SKIN TURGOR

To determine the skin turgor:• Grasps the skin on the back of the hand

between two fingers so that it is tented up.• Hold the skin in that position for a few

seconds and then release.• A hydrated person will have normal turgor,

in which the skin will snap rapidly back to its normal position.

• A person who is highly dehydrated person will have decreased turgor, in which the skin will remain elevated and then return slowly to its normal position.

FROSTBITE

FROSTBITE

Frostbite is caused by freezing of tissue, normally due to exposure below 32 degrees Fahrenheit. Seek treatment if suspected.

FROSTBITE

• Frostbite occurs in the body extremities (fingers, toes, feet, hands, tip of nose and ears) when the body part is exposed to intensely cold air or liquid.

• Freezing of the affected area begins and ice crystals begin forming in the skin.

• In severe cases, the body tissue dies and gangrene sets in, leading to the loss of the body part.

• Frostbite usually takes time to develop, but most people are unaware that it has begun.

• Frostbite occurs in two stages that have different treatments:

1) Early Stage 2) Late Stage

• NOTE: Frostbite may accompany Hypothermia so use caution, treat for both if needed and continue to monitor.

Wind Chill Temperature Table

Read right and down from the Air Temperature line. For example, if the temperature is 25°F and winds are blowing at 35 mph, the wind chill index would be 7°F, which little danger of frostbite; however frost bite can occur after 2 hours in dry, exposed skin.

Wind Chill Temperature Table Guidance

Early Stage

of Frostbite

Symptoms:• Skin turns from red to white and waxy• Numbness in the affected area

Treatment:• Warm the affected area using body heat.

Hands and feet can be placed in another team member’s armpit for warmth.

• Patient will probably sense tingling or burning in the affected area as it is re-warmed.

• DO NOT MASSAGE A FROSTBITTEN BODY PART

LATE STAGE FROSTBITE

(if early stage is not treated)

Symptoms:Skin turns mottled or blotchy,

yellow, and finally greyish-blue.

Treatment forLate Stage Frostbite

Treatment:• Transport the patient to medical care immediately.• If transport is not immediately available, immerse

the affected area in warm water (98-105°F) until circulation and re-warming occurs. Do not let the affected part(s) touch the sides of the container the body part is immersed in. Continue to refresh the water in order to keep it the same temperature as consistently as possible.

• Note: DO NOT attempt to thaw frostbitten tissues if there is a possibility they could freeze again. The more often the tissue freezes and thaws, the deeper the damage

• DO NOT MASSAGE A FROSTBITTEN BODY PART, it will cause more damage.

• Do NOT use any heating fire to treat frostbite. Victims cannot feel the frostbitten tissue and can be burned easily.

• Place cotton or gauze between fingers and toes to keep them seperated and wrap loosely with sterile gauze.

COLD WEATHER SAFETYIS NO JOKE!

It’s worth mentioning again…

When prevention fails, it is critical that everyone is able to recognize and treat cold weather injuries.

SUMMARY

By now you should be able to take steps to prevent cold weather injuries and recognize

and treat those that do occur

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