ColdRelated Emergencies

1
Chapter 20

• Cold-Related Emergencies

2
Cold-Related Emergencies

• Normal body temperature is 98.6F.
• 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 3.6F 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

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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

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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

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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
  (32F)
• Frostnip
• Freezing is limited to skin surface
• Frostbite
• Freezing occurs deeper in skin
• Frostbite more common in military, mountain
  climbers, explorers.

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Frostnip

• Water freezes on skin surface
• Serious could signal impending frostbite

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Recognizing Frostnip

• Red, swollen skin
• Painful
• Dry, cracked, sensitive skin from repeated
  frostnip to same spot

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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)

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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

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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

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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 95F
• 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 30-45 seconds.
• Start CPR immediately if immersion occurred.
• Handle gently.
• Must be evaluated by physician.

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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

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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
  95F.
• Change in mental status
• Disorientation, apathy, changes in personality
• Shivering
• Cool abdomen
• Low core body temperature (rectal)

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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 60F
• 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 90F

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 9-1-1.
• 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 90F

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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 9-1-1.
• 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.