1. Hypothermia
Brian & Evan

2. What is Hypothermia?
Hypothermia is a medical emergency that occurs when your body loses heat faster than it can produce heat, causing a dangerously low body temperature.
Normal body temp is around 98.6 F (37 C)
Hypothermia occurs as body temp drops below 95 F (35 C)

3. Symptoms of Hypothermia
Shivering
Slurred speech or mumbling
Slow, shallow breathing
Weak pulse
Clumsiness or lack of coordination
Drowsiness or very low energy
Confusion or memory loss
Loss of consciousness
Bright red, cold skin (infants)

4. Physiology: Temperature Homeostasis
Four ways heat is lost:
Radiation (65%)
Evaporation (25%)
Convection (5-10%)
Conduction (2-5%) (except in water--- 32x more conductivity in water than air)

5. Physiology: (Mild Hypothermia) Your Bodies response to heat loss
Core Body Temp = F
- Shivering (not under voluntary control)
- Disabled from Complex motor function
- Vascular constriction (Toes, Fingers, etc)

6. Physiology: (Moderate Hypothermia) Your Bodies response to heat loss
Core Body Temp = F
Reduced level of consciousness
Loss of fine motor function - especially in hands
Slurred speech
Violent shivering
Irrational behavior (taking layers off)

7. Physiology: (Severe Hypothermia) Your Bodies response to heat loss
Core Body Temp = F
Shivering arrives in waves… Violent intervals
The body shuts down on shivering to conserve glucose
Casualty falls to the ground..bundles up to conserve heat
Muscle rigidity develops because peripheral blood flow is reduced and due to lactic acid and carbon dioxide buildup in the muscles
Pale skin
Pupils Dilate
Pulse decreases
At 86 F the body is in state of “Metabolic Icebox” - They look dead, but are still alive

8. Body Heat Production (Positive Factors)
Limit Shivering By:
Fitness
Fuel Stores (glycogen)
Fluid Status
Food Intake

9. Heat Retention + Heat Production < Cold Challenge = Hypothermia
Heat Retention = Insulation, Body Fat, Surface to Volume Ratio, Shell to Core Protection
Heat Production = Exercise, Shivering
Cold Challenge = Temperature, Wetness, Wind

10. Examples of Hypothermia situations
Submerged in cold water (ex. Ice fishing, swimming in superior, canoe)
Hiking
Skiing/Snowboarding
Snowmobiling
Car breaks down
Sweating, Rain (wet)
Wind (Blowing, Moving, Biking)

11. Immersion Hypothermia
Significant risk in waters colder than 25 C and 72 F
0= 32
4=39.2
10=50
21=69.8

13. Risk Factors Exhaustion Older age Very young age
Mental problems (judgement related)
Alcohol and drug use
Certain medical conditions
Medications
Shelter

14. (B) Alcohol
MYTH: Alcohol warms your body which can actually help prevent hypothermia
Alcohol lowers the core body temperature
“Alcohol is a vasodilator, meaning that it causes your blood vessels to dilate, particularly the capillaries under the surface of your skin. Thus, the volume of blood brought to the skin’s surface increases, making you feel warm”
Minimizes blood flow to the skin in order to keep core body temperature up
Alcohol reduces the body's ability to shiver - yet another method to keep warm

15. Prevention COLD Dress young kids with extra layer
Cover
Overexertion
Layers
Dry
Dress young kids with extra layer
Fluids and Carbohydrates
Bring kids inside as soon as they start shivering
Be prepared for any trips in the cold
Be smart around water
Avoid alcohol

16. Situational Response Survive a fall through the Ice:
Once in the cold water, your body's cold shock response, called the "torso reflex" will make you want to gasp for air and hyperventilate because your heart rate accelerates rapidly, but you must avoid doing so
Wears off in 2-3 minutes
Keep Calm and DO NOT PANIC
Remove any heavy objects
Focus Energy on getting out
3-5 minutes before muscle shutdown
Get horizontal and kick your legs
Let water drain
Roll your body across the ice once you're out

17. Treatment First-Aid Be gentle with the person
Get them in a dry, warm location
Remove wet clothing
Monitor breathing
Warm beverage if alert
Don’t apply direct heat
Medical Treatment
Passive rewarming
Blood rewarming
Warm intravenous fluids
Airway rewarming

18. Resources