1. Cold Weather Survival
(Notes)

2. RADIATION
I R waves radiate from body due to temp. gradient. [Heat flows hot to cold] Key factors: Surface Area + Gradient

3. Direct contact between objects.
Key Factor: Density [Water conducts 25x faster than air] Ground Steel
CONDUCTION

4. CONVECTION
Conduction to a moving substance molecules heat up and move away. New cold molecules move in. Key Factors: Density [Water vs. air] speed of movement. [Ex. Wind chill.]

5. EVAPORATION
Perspiration/Respiration air heated and moisturized to breath. Insensible Perspiration: Sweat to keep humidity at 70% next to skin. Key Factor: Liquid decreases, Increases Susceptible to hypothermia.

7. ~ Insulation [Layering and type]
RESPONSE TO COLD
Heat Retention
~ Size Shape
~ Insulation [Layering and type]
~ Fat
~ Shell/Core of body
Cold Challenges
~ Temperature
~ Wetness
~ Wind
~ Density [H20]
Heat Production
~ Exercise – Fitness – Fuel Stores – Fluid – Food
~ Shivering

8. How Your Body Regulates Core Temperature
Vasodilation - increases surface blood flow, increases heat loss=cooling
2. Vasoconstriction - decreases blood flow to periphery, decreases heat loss.

9. How Your Body Regulates Core Temperature (Continued…)
3. Sweating = cooling
4.Shivering - generates heat through increase in chemical reactions required for muscle activity. Visible shivering can maximally increase surface heat production by 500%. However, this is limited to a few hours because of depletion of muscle glucose and the onset of fatigue.

10. How Your Body Regulates Core Temperature (Continued…)
5. Increasing/Decreasing Activity will cause corresponding increases in heat production and decreases in heat production.
6. Behavioral Responses - putting on or taking off layers of clothing will result in heat regulation

11. CORE BODY TEMP 98.6 degrees F ~ Above 105 deg. F enzymes denature.
~ Below 98.6 deg. F chemical Rxn slow.
~ Core= Internal organs esp. Heart, lungs, and brain.
~ Periphery= Appendages, skin, and muscle.
* Core is essential to overall metabolic rate.
CORE BODY TEMP

12. Metabolism increases = Heat generated increases
Metabolism increases = Heat generated increases. Exercise increases metabolism to get energy to move muscles. Cold core temp slows chem. Rxns. Of metabolism. Impairs body’s ability to generate heat.

13. Brain directs metabolism. Heart/Lungs deliver 02 for met. and brain.
H20 + Sugar + 02  Co2 + Energy
Brain directs metabolism. Heart/Lungs deliver 02 for met. and brain.

14. Hypothermia
Decrease in core temp. that impairs normal muscle and brain function. Hypo.= Decrease in core body temp. that causes problems w/muscle and brain function.

15. Conditions Leading To Hypothermia
Cold
Wind
Wet
fatigue
food intake
dehydration
alcohol

16. STAGES OF HYPOTHERMIA STAGE CORE TEMP SIGNS MILD 95-99
FEEL COLD, GOOSE BUMPS, SHIVERING,
HANDS NUMB, DEXTERITY LOSS
MODERATE
95-93
90-93
INTENSE SHIVERING, LOSE COORDINATION, SLURRED SPEECH, DAZED, STUMBLES
SEVERE
90-86
86-82
STOPS SHIVERING,SKIN BLUE,CANT WALK,CONFUSED, NO PULSE IN WRIST, MUSCLE RIGIDITY, SEMI-CONCIOUS, LOW PULSE & RESP. RATE
DEATH
SLOW, ERATIC BREATHING, CARDIAC FAILURE

17. At 90 degrees F, body starts to shut down all peripheral blood flow and decreases breathing and heart rate.

18. Hypothermia Assessment
~ Can stop shivering = Mild
~ Can’t count 100 – 1 by 9s = Moderate
~ Fails drunk tests = Moderate
~ No radial pulse = Severe
~ Stop shivering = Severe
~ Curled in fetal ball, pull out arm if it curls back up = Alive

19. Treatment Reduce Heat Loss ~ Clothing ~ Dry ~ Shelter 2. Food and H20
~ Carbos = Fast -->

20. Protein = Increase in heat/g Fat = More cal/g *Warm liquids
*No alcohol, caffeine, tobacco.
External Heat Source
Neck, armpits, and groin.

21. Vasoconstriction Hand/foot at 59 degrees F. Max. Construction
At 50 degrees F periods of blood flow to increase heat in hand, 5-10 min. cycle.
Acclimatization = Strong response with short interval.

22. Cause: Freezing of all skin layers muscle and/or bone.
Frost Bite
Symptoms:
White wooden skin.
All layers of skin hard
Numbness
Cause: Freezing of all skin layers muscle and/or bone.

23. Tissue Freezing Ice crystals form in cells. Fluid flows into cells.
Cells break due to tearing by crystals or “pop” when too much H20 enters.
**Do not rub frozen tissue**
(Increase breakage by crystals.) 

24. Cell death  Tissue death. Tissue freezes at 28 degrees F.
Areas with high surface area to volume ratios most susceptible ears, nose, fingers, and toes.

31. Treatment Re-warm in 105-110 degrees F water.
Circulate water and maintain temp by adding H20.
Wrap in sterile gauze.
Don’t use re-warmed part.
**Do not let refreeze!!**

34. Cause: Frozen top layers of skin.
Frost Nip Symptoms:
White Waxy skin.
Top layer hard and rubbery.
Deeper tissue still soft.
Numbness
Blisters may occur = Popped cells.
Cause: Frozen top layers of skin.

35. Re-warm with warm air or place against warm body part.
Treatment
Re-warm with warm air or place against warm body part.
Do not rub!

41. Frozen Cornea
Rapid re-warming w/compress or warm hand over closed eye.
Patch for hours.

42. Eyelashes Frozen Together Warm with hand. Snow Blindness
Sunburn of eye.
8-12 hrs. later eyes dry irritated light hurts, swelling eyelids.

44. C. O. L. D. Keep it Clean Avoid Overheating
Wear it Loose and in Layers
Keep it Dry

45. Dressing For Cold Layers
1st Layer
2nd Layer
3rd Layer
Must move moisture away – underwear.
Insulating layer. Moves moisture out, traps warm in
Completes moisture transfer.
Wicking
Warming or Insulation
Weather