2. Cold Weather Survival (Notes)

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

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

5. 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.]

6. 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.

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

9. How Your Body Regulates Core Temperature 1.Vasodilation - increases surface blood flow, increases heat loss=cooling 2. Vasoconstriction - decreases blood flow to periphery, decreases heat loss.

10. 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.

11. 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

12. 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.

13. 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.

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

15. 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.

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

17. STAGES OF HYPOTHERMIA STAGECORE TEMP SIGNS MILD95-99FEEL COLD, GOOSE BUMPS, SHIVERING, HANDS NUMB, DEXTERITY LOSS MODERATE95-93 90-93 INTENSE SHIVERING, LOSE COORDINATION, SLURRED SPEECH, DAZED, STUMBLES SEVERE90-86 86-82 STOPS SHIVERING,SKIN BLUE,CANT WALK,CONFUSED, NO PULSE IN WRIST, MUSCLE RIGIDITY, SEMI-CONCIOUS, LOW PULSE & RESP. RATE DEATHSLOW, ERATIC BREATHING, CARDIAC FAILURE

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

19. 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

20. Treatment 1.Reduce Heat Loss ~ Clothing ~ Dry ~ Shelter 2. Food and H 2 0 ~ Carbos = Fast  --> -->

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

22. 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.

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

24. Tissue Freezing Ice crystals form in cells. Fluid flows into cells. Cells break due to tearing by crystals or “pop” when too much H 2 0 enters. **Do not rub frozen tissue** (Increase breakage by crystals.) 

25. 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.

28. http://atlases.muni.cz/atl_en/_reference/01+00691+.html

32. 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!!**

35. 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.

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

45. Frozen Cornea Rapid re-warming w/compress or warm hand over closed eye. Patch for 24-48 hours.

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

48. Dressing For Cold 1 st Layer 2 nd Layer3 rd Layer Must move moisture away – underwear. Insulating layer. Moves moisture out, traps warm in. Completes moisture transfer. Layers 70% body heat escapes through extremities.