1. Hypothermia

2. Hypothermia
Newspapers usually refer to hypothermia as death due to exposure, the person froze to death. Hypothermia is defined as a decrease in the core body temperature to a level at which normal muscular and cerebral functions are impaired. One common misconception is that hypothermia occurs at cold temperatures. Occurs more frequently at temperatures above 32oF (between 30-50) little kids at pools.

3. Heat Production Internal sources-muscular activity and food
Eat fatty foods when out doors in cold weather
Keep moving when outdoors in cold weather
External sources-sun, fire, hot liquids, other bodies
Set little kids in sun when shivering by pool or cuddle with them
Fires are easy to build and can be life savers
Warm up with hot chocolate

4. Heat Loss There are five ways to loose heat from your body.
Radiation-heat loss by EMW due to a temperature gradient, you shine away heat
Conduction-heat loss by contact with cold objects, wet snow, cold rocks, bare metal
Water takes away heat 25 times faster than air (stay dry stay alive), water chill

5. Convection-a process of conduction when one object is in motion, a constant replacing of warmed objects for cold.
Hot air rises
Wind chill is and example of convection, tables only show heat loss of warm body due to wind
Evaporation-heat loss by converting water to water vapor (600 cal/gram)
Sweating, even in dry winter air
Respiration-exhaling air lose heat and moisture
Heat Loss

6. Conditions The conditions that cause hypothermia: Cold temperatures
Improper clothing and equipment
Wetness
Fatigue, exhaustion
Dehydration
Poor food intake
Wind
Alcohol

7. Signs and Symptoms Watch for the “umbles”
Stumbles, mumbles, fumbles and grumbles; all show changes in motor coordination and levels of consciousness.
Mild hypothermia-core temp
Shivering-not under voluntary control
Can’t do complex motor functions (skiing) can walk.
Vasoconstriction to periphery (blue lips, hands)

8. Signs and Symptoms Moderate hypothermia-core temp 95.0-93.0
Dazed consciousness
Loss of fine motor coordination-can’t unzip
Slurred speech
Violent Shivering
Irrational behavior-paradoxical undressing
I don’t care attitude (I just want to sit and rest)

9. Signs and Symptoms Severe Hypothermia-core temp 92.0-86.0
Shivering in waves, until shivering stops (conserving fuel)
Person falls to ground to fetal position
Muscle rigidity develops due to lack of blood flow
Skin is pale
Pupils dilate
Pulse rate decreases
At 90 the body moves into hibernation, shutting down blood flow, heart rate, and breathing rate
At 86 the body is in a state of metabolic icebox, the person looks dead but is still alive (mammalian dive reflex)

10. Signs and Symptoms 86 to 82oF appears dead. In cardiac arrest
People come back from lower temps.
Skin temperature is lower than core temp
Don’t give up until warm and dead

11. Assessing Hypothermia
If shivering can be stopped voluntarily-mild
Ask person to count back from 100 by 9’s if can’t –moderate
If shivering can’t be stopped-moderate to severe
No radial pulse but person is alive-severe
If person is in fetal position and appears dead, open their arm up, if it curls back up the person is still alive-severe

12. Preventing Hypothermia
Cold challenges must be less than heat production and retention.
Cold challenges
Temperature
Wet
Wind
Heat Retention
Size and shape of body (Eskimo/Northern European vs. Masai
Insulation-layering and type of clothes
Fat-whales, seals, me
Shell/core-shell of body acts as an insulator to the core
Heat production
Exercise
Fitness level
Fuel stores of glycogen
Fluid levels of body
Food intake

13. Treating Hypothermia Reduce heat loss Eat food and liquids
Put on more clothes
Put on dry clothes
Increase physical activity
Seek shelter
Eat food and liquids
Carbohydrates-(5 cal/g) quick energy, good for mild hypothermia
Proteins- (5 cal/g) long release
Fats- (9 cal/g) long release, requires water for conversion

14. Treating Hypothermia Food you should eat Foods to avoid Add heat
Hot liquids-calories plus warms your core (hot chocolate).
Sugars-quick start energy (like kindling)
Gorp-has both sugars (kindling) and fats/proteins (logs)
Foods to avoid
Alcohol-a vasodilator-increases peripheral heat loss
Caffeine- a diuretic-causes dehydration
Tobacco-a vasoconstrictor, increases risk of frostbite
Add heat
Fire or other external heat source
Body to body contact. Get into sleeping bag, in dry clothing with a normothermic person in lightweight dry clothing.

15. Treating Severe Hypothermia
Reduce heat loss
Hypothermal wrap-make sure they are dry and wrap them in multiple sleeping bags, wool blankets to create a 4” shell around them. Do not put another person in with them.
Food and water
Use only warm sugar water to give energy(stomach has shut down) dilute Jell-O water has both sugar and proteins.
Have them empty bladder, urine steals heat from organs.
Add heat
Apply heat packs (warm water bottles, towels etc…) at the neck, armpits, and groin.
Mouth to mouth transfers heat to victims lungs
After drop-if warm periphery to quickly cold acidic blood enters the core and cause a heart stoppage.
No CPR-heart rate is very slow (2-3 beats/minute)

16. Cold Injuries Factors influencing cold injuries Temperature Wind chill
Dry skin
Insulation
Exposed skin
Previous cold injuries
Cramped position or restricting clothing
Dehydration
Alcohol

17. Cold Injuries
Cold Induced Vasodilatation-when extremity is cooled to 59 degrees vasoconstriction stops blood flow to the extremity. If extremity is cooled further vasoconstriction is interrupted with periods of vasodilatation. This occurs in 5 to 10 minute cycles and provides protection from the cold. Can train your body to do this.
Inuit / Minnesota six queens

18. Cold Injuries Freezing tissue
Ice crystals form in cells, tearing of cells results
There is a burning/biting sensation as skin freezes.
Do not rub frozen skin, it will cause tearing of cells.
Cells can rupture during thawing due to high salt concentrations, thaw slowly.
Distal areas with high surface areas are most susceptible-ears, nose, fingers and toes.

19. Frostbite There are three different degrees of frostbite.
Frostnip-freezing of the top layers of skin
Reversible
Skin is white and waxy, top feels hard and rubbery
Feels tingly or stinging
See on cheeks, earlobes, fingers and toes
For treatment, do not rub, place in armpit or groin.
Superficial Frostbite-all layers of skin are froze
Skin is white and wooden feeling
Skin is numb or no feeling
Blisters form from liquids from ruptured cells
Deep Frostbite-includes freezing of muscle and or bone
Difficult to rewarm without further damage

20. Treatment of Frostbite
Superficial frostbite can be rewarmed just as frost nip.
Deep frostbite
Immerse in warm water bath of degrees for 20 to 40 minutes. Make sure to maintain the temperature. Do not use dry heat, to hot.
Once rewarmed there is significant pain.
Wrap in gauze and protect from motion or refreezing.
If you can’t protect from refreezing, leave frozen it will not cause any more harm, it is already done.
gau