This document discusses cold-related emergencies and injuries that can occur when the body loses heat faster than it can produce it. It describes how cold affects the body through vasoconstriction and shivering. It explains the four mechanisms of heat loss from the body and factors that increase susceptibility to cold injuries. Specific cold-related injuries are outlined such as chilblain, trench foot, frostnip, and frostbite. Hypothermia, a life-threatening condition, is also described along with its symptoms, types, and care. The document stresses the importance of preventing dehydration in cold conditions.

1. Chapter 20
Cold-Related Emergencies

2. Cold-Related Emergencies
• When surrounded by air or water cooler
than body temperature, body loses
heat.
• Normal body temperature is 98.6°F.
• If heat escapes faster than the body
produces it, the body temperature falls,
and cold injuries result.

3. How Cold Affects the Body (1 of 2)
• The body has two internal mechanisms to
maintain body temperature.
• Vasoconstriction
• Tightening of blood vessels
• Can cause discomfort, numbness, loss of
dexterity, cold injuries
• Shivering
• Stops when core temperature falls
between 86 and 90°F

4. How Cold Affects the Body (2 of 2)
• Physical activity produces heat.
• Heat loss increases if clothes become wet
with perspiration.
• Susceptibility can be minimized by:
• Proper hydration and nutrition
• Avoiding alcohol, caffeine, and nicotine
• Limiting periods of inactivity

5. Heat Loss from the Body (1 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

6. Heat Loss from the Body (2 of 2)
• Four mechanisms of
heat loss (cont’d):
• Radiation
• Heat given off
to cooler air
• Accounts for
the greatest
heat loss

7. Susceptibility to Cold Injury
• Physically unfit
• Dehydration
• Very lean people
• Elderly people
• Alcohol, caffeine
• Nicotine
• Inadequate nutrition, illness, injury
• Experienced a previous cold injury

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

9. Effects of Water
• Water can conduct heat away from
the body much faster than air of the
same temperature.
• Wet clothing accelerates heat loss.

10. Effects of Wind
• Wind increases heat loss from skin
exposed to cold air.
• Windchill is the combined effect of
the ambient temperature and wind
speed.

11. Effects of Metal and Liquid
Fuels
• Can conduct heat away from
skin rapidly
• Contact can cause almost
instantaneous freezing

12. Minimizing Effects of Cold on
the Body (1 of 2)
•Layering
• Undergarment
removes
perspiration
• Wicking
properties
© Simon Price/Alamy Images

13. Minimizing Effects of Cold on the
Body (2 of 2)
• Middle layer insulates.
• Should be effective when wet.
• Synthetics are better than natural fibers.
• Wool
• Outer layer protects against wind.
• Waterproof
• Wind resistant
• “Breathable”
• Hat

14. Nonfreezing Cold Injuries
• Can occur when conditions
are cold and wet and hands
and feet cannot be kept warm
and dry

15. Chilblain
• Is painful
• Causes little or no
permanent damage
• Can develop in 3 to 6 hours

16. Recognizing Chilblain
• Swollen skin
• Skin is tender, hot to the
touch, and possibly itchy.
• Blisters
• Aching, prickly sensation,
numbness

17. Care for Chilblain
• Get victim out of cold.

18. Trench Foot
• Develops when skin on the feet is exposed to
moisture and cold for 12 hours or longer.
• Caused by:
• Wearing wet boots and shoes
• Prolonged immersion of the feet in cold
water
• Rubberized or tight-fitting boots increase risk.

19. Recognizing Trench Foot and
Immersion Foot
• Itching, numbness, tingling pain
• Swollen feet and pale skin cold to touch
• Red or bluish blotches on the skin
• Sometimes open weeping or bleeding

20. Care for Trench Foot
• Dry the skin.
• Rewarm foot gradually.
• Care for open weeping areas.
• Use mild soap and water.
• Apply a breathable dressing.

21. Freezing Cold Injuries
• Occur when air temperature is below freezing
• Frostnip
• Freezing is limited to skin surface.
• Frostbite
• Freezing extends into the flesh.

22. Frostnip
• Frostnip is
caused when
water on the skin
surface freezes.
Courtesy of Neil Malcom Winkelmann

23. Recognizing Frostnip
• Red and sometimes swollen
skin
• Painful
• Repeated frostnip can dry the
skin.

24. Care for Frostnip
• Gently warm affected area.
• Do not rub the affected area.

25. Frostbite
• Two ways of
damage:
• Tissue freezing
• Obstruction of blood
supply to the tissue
• Affects feet, hands,
ears, and nose

26. Recognizing Frostbite (1 of 2)
• White, waxy, or grayish yellow skin
• Part feels cold and numb
• Tingling, stinging, aching
• Stiff or crusty skin
• Underlying tissue is soft

27. Recognizing Frostbite (2 of 2)
Indications of deep
frostbite:
•Part feels cold, hard, and
solid and cannot be
depressed.
• Blisters
• Pale, waxy skin
• Painfully cold part
suddenly stops hurting

28. Classifications of Frostbite
• First-degree
• Warm, swollen,
and tender
• Second-degree
• Blisters form.
• Enlarges over
several days.
• Third-degree
• Small blisters with
reddish-blue or
purplish fluid
• Red or blue skin
• Might not blanch
• Fourth-degree
• No blisters or
swelling.
• Part remains
numb, cold, and
purple.

29. Care for Frostbite (1 of 2)
• Get victim to warm area.
• Remove wet clothing and constricting items.
• Seek medical care.
• If affected part is partially thawed:
• Place part in warm water.
• Maintain water temperature.
• 20 to 40 minutes
• Give pain medication.
• Apply warm cloths to ear or facial injuries.

30. Care for Frostbite (2 of 2)
• After thawing:
• Treat the victim as a stretcher case.
• Protect area from contact with clothing and
bedding.
• Place dry gauze between toes and fingers.
• Slightly elevate the affected part.
• Apply aloe vera gel.
• Provide pain medication.

31. Hypothermia
• A life-threatening condition in which the
body’s core temperature falls below 95°F
• Body loses more heat than it produces.
• Heartbeat/breathing may be undetected
• Begin CPR immediately.
• Consider whenever victim’s behavior and
history and the weather conditions indicate
abnormal heat loss

32. Types of Exposure
• Acute
• Usually in
water
• 6 hours or less
• Subacute
• 6 to 24 hours
• Land or water
• Chronic
• Occurs on land
• Exceeds 24
hours

33. Hypothermia Symptoms
• Change in mental status
• Disorientation
• Apathy
• Changes in personality
• Shivering
• Cool abdomen
• Low core body temperature

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 is below 60°F.
• Chest is frozen.
• Submerged in water for more than 60 minutes.
• A lethal injury exists.
• Transport will be delayed.
• Rescuers are endangered.

35. Recognizing Mild Hypothermia
• Vigorous, uncontrolled shivering
• Decreased mental skills
• Slurred speech
• Difficulty using fingers or hands
• Staggers while walking
• 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.
• Prevent heat loss.
• Cover the victim with a vapor barrier.
• Keep the victim horizontal.
• Call 9-1-1.
• Allow the victim to shiver.
• Give warm, sugary drinks.

37. Recognizing Severe
Hypothermia
• No shivering
• Ice cold and blue skin
• Stiff and rigid muscles
• Altered mental status
• Slow breathing and pulse
• Might appear dead.
• Core body temperature is below 90°F.

38. Care for Severe Hypothermia
• Get victim out of the cold.
• Handle gently.
• Prevent heat loss.
• Cover with vapor barrier.
• Keep victim horizontal.
• Call 9-1-1.
• When remote, warm by available heat.

39. Adding Heat
• Problems with rewarming:
• Warm water immersion requires a lot of
warm water and a bathtub.
• Body-to-body contact in insulated sleeping
bag is not better than shivering.
• No evidence that chemical heating pads
are capable of rewarming a hypothermic
victim.

40. Dehydration (1 of 2)
• Occurs because of unperceived fluid loss
combined with inadequate fluid intake.
• Cold weather: fluid lost through breath
• Drink even if not thirsty
• Inactive: drink two quarts of water daily
• Color and volume of urine indicate
hydration.

41. Dehydration (2 of 2)
• Unmelted snow and ice should not be
consumed for water.
• Irritates the mouth.
• Wastes body heat
• Lowers body temperature
• Be sure snow and ice are disinfected
before consumption.