1. Cold-Related Emergencies
Chapter 20
Cold-Related Emergencies

2. Cold-Related Emergencies
Normal body temperature is 98.6°F.
Body loses heat when surrounded by air or water that is cooler than the body.
Body temperature falls
Cold injuries can result.

3. How Cold Affects the Body (1 of 2)
Biologic defense mechanisms protect body
Vasoconstriction
Tightening of blood vessels
Can cause discomfort, numbness, loss of dexterity, cold injuries
Shivering produces body heat.
Stops when core temperature falls too low or when there is no fuel.

4. How Cold Affects the Body (2 of 2)
Physical activity produces heat.
Heat loss after exertion if clothes are wet
Proper hydration and nutrition help prevent cold injuries.
The colder the temperature, the greater the potential of body heat loss.
Physical changes from cold exposure can impair ability to perform manual tasks.

5. Heat Loss From the Body (1 of 2)
Body temperature maintained by balance of heat production and loss
Shivering rapidly consumes calories.
Heat loss occurs primarily through skin.

6. Heat Loss From the Body (2 of 2)
Four mechanisms of heat loss:
Conduction
Direct contact with colder object
Convection
Loss of heat by air blowing over skin
Evaporation
Conversion of liquid on skin to vapor
Radiation
Heat given off to cooler air
Primary method of heat loss

7. Susceptibility to Cold Injury
Physically unfit
Dehydration
Very lean people
Elderly
Alcohol, caffeine
Smoking, chewing tobacco
Inadequate nutrition, illness, injury
Previous cold injury

8. Effects of Altitude Temperature, windchill are considerations
Air temperature drops 3.6°F every 1,000 feet.
Winds more severe
More susceptible to frostbite above 8,000 feet

9. Effects of Water Conducts heat away from body faster than air.
Body heat loss occurs 25 times faster with wet clothing.
Plunging into cold water can cause irregular heartbeat, gasping, hyperventilation.
These can cause water inhalation, heart failure, drowning.

10. Effects of Wind Increases potential for body heat loss
Windchill index integrates wind speed and air temperature.
Helps estimate risk of cold injury.
Artificial wind can increase heat loss.

11. Effects of Metal and Liquid Fuels
Can conduct heat away from skin rapidly.
Contact can cause almost instantaneous freezing.
Must use great care when handling.

12. Minimizing Effects of Cold on the Body
Adequate clothing is key
Layered clothing helps maintain proper body temperature.
Undergarments
Should wick away perspiration
Middle layer
Synthetic pile, fleece, or wool
Outer layer
Waterproof, wind resistant, breathable, with zipper

13. Nonfreezing Cold Injuries
Can occur when conditions are cold and wet, hands and feet cannot be kept warm and dry
Chilblain
Trench foot

14. Chilblain Painful, but causes little or no permanent damage
Can develop in 3 to 6 hours if exposed to cold and moisture

15. Recognizing Chilblain
Swollen skin
Tender, hot to touch, itchy
Blisters
Aching, prickly sensation
Numbness

16. Care for Chilblain
Get victim out of cold.

17. Trench Foot Serious injury, also called immersion foot
Develops when feet exposed to moisture and cold for 12 hours or longer
Moisture softens skin, tissue loss and infection occur
Crippling injury can occur

18. Recognizing Trench Foot
Itching, numbness, tingling pain
Swollen feet, pale skin cold to touch
Red, bluish blotches on skin
Sometimes open weeping, bleeding

19. Care for Trench Foot Dry the skin. Rewarm foot gradually.
Cleanse weeping areas with mild soap and water, apply breathable dressings.

20. Freezing Cold Injuries
Occur when air temperature is below freezing (32°F)
Frostnip
Freezing is limited to skin surface
Frostbite
Freezing occurs deeper in skin
Frostbite more common in military, mountain climbers, explorers.

21. Frostnip Water freezes on skin surface
Serious — could signal impending frostbite

22. Recognizing Frostnip Red, swollen skin Painful
Dry, cracked, sensitive skin from repeated frostnip to same spot

23. Care for Frostnip Gently warm affected area.
Place against warm body part.
Blow warm air on area.
After, area can become red and tingling.
Do not rub.

24. Frostbite Occurs when temperatures drop below freezing
Tissue can actually freeze
Blood supply obstructed
Affects feet, hands, ears, nose
Most severe consequence = gangrene (dead tissue)

25. Recognizing Frostbite (1 of 2)
White, waxy, or grayish yellow skin
Cold and numb
Tingling, stinging, aching
Stiff or crusty surface, soft underneath
Deep frostbite:
Cold, hard, solid
Blistering
Cold, pale, waxy skin
Pain stops

26. Recognizing Frostbite (2 of 2)
First-degree
Warm, swollen, tender
Second-degree
Blisters minutes to hours after thawing, enlarge over several days
Third-degree
Small blisters, reddish blue/purplish fluid
Fourth-degree
No blisters, no swelling
Numb, cold, white to dark purple

27. Care for Frostbite (1 of 2)
Get victim to warm area.
Remove wet clothing.
Remove items that could impair circulation.
Seek medical care.
If affected part is partially thawed or victim is remote:
Place part in warm water. Add warm water to maintain water temperature.
Ear or facial injuries: apply warm, moist cloths.

28. Care for Frostbite (2 of 2)
After thawing:
Place on stretcher if feet affected.
Protect area from contact with clothing, bedding.
Place dry dressings between toes and fingers.
Slightly elevate to reduce pain and swelling.
Apply aloe vera gel.
Provide aspirin (adults), or ibuprofen, or acetaminophen.

29. Hypothermia (1 of 3)
Life-threatening condition when core temperature falls below 95°F
Can occur even when temperature is above freezing, if windy, wet, or person is inactive
Can occur year round
Death results if untreated
Occurs rapidly during cold water immersion

30. Hypothermia (2 of 3)
Heartbeat, breathing, response to pain may not be detectable
Victim can still be alive.
Check circulation for seconds.
Start CPR immediately if immersion occurred.
Handle gently.
Must be evaluated by physician.

31. Hypothermia (3 of 3) Many different people susceptible.
Consider when behavior, history, and weather conditions indicate heat loss.
More likely if behavior is strange and victim was shivering.
Alcohol, medications can contribute
Very old, very young, and less fit are more susceptible

32. Types of Exposure Acute Heat loss occurs rapidly (6 hours or less)
Usually in water
Subacute
Heat loss over 6-24 hours
Land or water
Chronic
Long-term cooling greater than 24 hours
Occurs on land

33. Recognizing Hypothermia
Suspect in anyone with temperature less than 95°F.
Change in mental status:
Disorientation, apathy, changes in personality
Shivering
Cool abdomen
Low core body temperature (rectal)

34. Types of Hypothermia Mild to severe based on core body temperature
In severe cases, shivering stops.
Do not start CPR if:
Core body temperature less than 60°F
Chest is frozen.
Submerged more than 60 minutes
Lethal injury
Transport delayed
Rescuers endangered

35. Recognizing Mild Hypothermia
Vigorous, uncontrollable shivering
Grumbling, mumbling, fumbling, stumbling
Cool or cold skin on abdomen, chest or back
Core body temperature above 90°F

36. Care for Mild Hypothermia
Get victim out of cold.
Handle gently.
Replace wet clothing with dry clothing.
Cover head.
Cover with vapor barrier.
Keep victim horizontal.
Do not raise legs.
Do not let victim walk or exercise.
Call
Allow shivering.

37. Recognizing Severe Hypothermia
No shivering
Ice cold, blue skin
Stiff, rigid muscles
Altered mental status, not alert
Slow breathing and pulse
Victim might appear dead
Core body temperature below 90°F

38. Care for Severe Hypothermia
Get victim out of cold.
Handle gently.
Replace wet clothing with dry clothing.
Cover head.
Cover with vapor barrier.
Keep victim horizontal.
Do not raise legs.
Do not let victim walk or exercise.
Call
When remote, warm by any available heat source.

39. Adding Heat Problems with rewarming:
Warm water immersion requires a lot of warm water and a bathtub.
Hot baths can cause cardiac arrest.
Body-to-body contact in insulated sleeping bag is ineffective.
Use body-to-body rewarming only when delayed care or other methods unavailable.
Chemical heating pads are not effective.

40. Dehydration In cold weather, fluid is lost through exhaled breath.
Color and volume of urine indicate hydration.
Unmelted snow and ice should not be consumed; can lower body temperature.
If snow, ice are only available sources of water, melt before consuming.
Melted snow, ice should be disinfected before drinking.