Cold Related Injuries. Hypothermia, Frostbite & Trench foot

1. Classification, clinical features, treatment
Cold-related Injuries:
Hypothermia, Frostbite and
Trench Foot

2. Factors Increasing Risk of Cold Injuries/Illnesses
• Previous cold-related injury
• Predisposing health
conditions
• Fatigue, poor physical
condition
• Poor nutrition
• Dehydration
• Medication
• Alcohol
• Nicotine (Smoking)
• Age
• Improper clothing and
equipment
• Under-activity
• Over-activity
• Cold conditions:
– Temperature
– Wind
– Wetness
• Length of exposure

3. Definitions
Shell = skin, subcutaneous tissues and
extremities.
Temperature of the shell varies according to
environment
Core = brain, heart, deep vessels & organs
– are maintained at a steady
temperature

4. Definitions Continued:
Core Body Temperature
▪ Measured by rectal, esophageal,
or tympanic thermometer
▪ Oral temperatures read 1 degree
less than rectal

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6. Hypothermia
Hypothermia ("low heat”) is a potentially serious and fatal
health condition resulting from the body’s failure to maintain its
normal core temperature of 98.6°F (37ºC).
When exposed to cold conditions, your body begins to lose
heat faster than it can be produced. Prolonged exposure to cold
eventually uses up your body’s stored energy and your core
body temperature drops to 95°F (35ºC) or below.
The result is hypothermia.
Hypothermia is a
medical emergency!

7. Hypothermia
Body temperature - that is too low affects the brain,
making the affected person unable to think clearly or
move well.
This makes hypothermia
particularly dangerous because a
person may not realize it is
happening and may deny being
in any trouble.

8. Hypothermia
However, it can occur at warmer
temperatures as high as 65°F (18-19°C),
or more, if a person becomes chilled from
prolonged exposures to wetness (rain,
snow, submersion in cold water, or sweat)
and accompanying winds.
Generally, in cold dry environments,
hypothermia occurs over a period of
hours.
In cold water, core temperature can drop
to dangerous levels in a matter of
minutes.
Most cases of hypothermia occur in air
temperatures from 30°F to 40°F (0-5°C).

9. Immersion Hypothermia
Water
Temp
eratur
e in
Degre
es F
(Degr
ees C)
Exha
ustio
n or
Unco
nscio
usne
ss
Expe
cted
Time
of
Survi
val
32.5
(0.3)
Unde
r 15
min.
Unde
r 15
to 45
min.
32.5
Water transfers heat away from the human
body 25 times faster than air,
so even moderate water temperatures can
be dangerous in a relatively short time.

10. Stages of Hypothermia
Approximate
Core Body
Temperature
Mild
hypother
mia
37°С-
35°С
Moderate
hypother
mia
35°С -
33°С
Hypothermia progresses through three indistinct but
sequential stages as core body temperature continues to
decline:

11. Mild Hypothermia
• Shivering, mild to severe
• Sensation of cold, then pain in
extremities
• Pale, waxy, cold skin
• Numbness of hands
• Unable to perform complex tasks
(fumbling with items in the hand)
• Able to walk and talk
Signs/Symptoms
• Irritability
Physical Mental
If shivering can be stopped voluntarily • mild hypothermia

12. Moderate Hypothermia
• Intense shivering becomes
persistent and violent
• Sluggish; labored movements
• Stumbling
• Loss of fine motor coordination
in hands (fumbling)
Signs/Symptoms
• Confused, may appear alert
• Irrational behavior – “paradoxical
undressing” (person starts to
undress, unaware s/he is cold)
• Apathetic/flattened affect –
"I don't care” attitude"
• Withdrawn behavior
• Slurred speech, difficulty speaking
• Sluggish thinking
• Signs of depression
Physical ●
Mental
Watch for the “-umbles”
• stumbles
• mumbles
• fumbles
• grumbles

13. Severe Hypothermia
• Shivering stops
• Exposed skin blue or puffy
• Muscle coordination very poor,
muscle rigidity
• Stupor
• Can’t walk; falls to ground and
curls up into fetal position to
conserve heat
• Decreased pulse and
respiration rate
• Irregular heart rhythm
Signs/Symptoms
Physical
• Incoherent, irrational
behavior
• May be able to maintain
posture and appearance of
awareness
• Semi-conscious, drowsy
• Loss of awareness of others
• Amnesia, memory lapses
Mental

14. Possible Death from Hypothermia
• Erratic, shallow breathing
• May not be able to feel pulse
• Pupils dilated and fixed
• Cold, blue skin
• Unresponsive to any stimuli
• Pulmonary edema, cardiac
and respiratory failure
• Death possible below 78°F
Physical
• Brain activity seriously slowed
• Unconscious, appears
comatose or dead
Mental
Core body temperature below 28°C – 25°C
Worker may appear dead and
show all the accepted clinical
signs of death, but many of
these people have made
complete recoveries when re-
warmed.
“No one is dead until warm and dead”

15. Treatment of Hypothermia
Treatment depends on the severity of the hypothermia.
• Remove wet clothes from victim and replace with dry
clothes and/or wrap in warm blankets; cover the head.
• Move to a warm environment.
• Do not exercise to warm up.
• Do not re-warm person in a warm bath or by
massaging or rubbing.
• Drink a warm (not hot) sugary drink.
Avoid drinks with caffeine (coffee, tea,
or hot chocolate) or alcohol.
• Transport victim to an emergency
medical facility for evaluation.
Mild Hypothermia
Handle the victim gently
and minimize his or her
exertion.

16. Treatment of Hypothermia (con’t.)
• Call for emergency help.
• Follow the procedures on the
preceding slide.
In addition:
• Cover all extremities completely,
place very warm objects, such as
hot packs or water bottles on the
victim's head, neck, chest and
groin. Arms and legs should be
warmed last.
Moderate Hypothermia
Handle the victim gently.
Rough handling can cause
heartbeat irregularities and
death.

17. Treatment of Hypothermia (Con’t.)
• Call for emergency help.
• Give CPR if necessary.
• Follow the procedures for treating mild
hypothermia.
• Do not apply external heat to re-
warm (hot water bath, heat lamp, electric
blanket, electric heater, etc.).
• Transport the victim to an emergency medical
facility as soon as possible.
Severe Hypothermia
Handle the victim very gently.
Transport to hospital for
treatment as soon as possible.

18. Frostbite
Pathophysiology Cutaneous circulation and thermal homeostasis
The cutaneous circulation plays a major role in maintaining thermal homeostasis.
The skin loses heat more easily than it gains.
Normal cutaneous flow is 200-250 mL/min
At 15°C, maximal vasoconstriction is reached, with blood flow measured at 20-50
mL/min
Below 15°C, vasoconstriction is interrupted by rhythmic bursts of vasodilation
occurring 3-5 times per hour and lasting 5-10 minutes; these bursts are more
frequent and longer in individuals acclimated to the cold, making them less prone
to frostbite injury
At 10°C, neurapraxia occurs, resulting in loss of cutaneous sensation
Below 0°C, negligible cutaneous blood flow allows the skin to freeze;
Without circulation, skin temperature drops at a rate exceeding 0.5°C per minute;
smaller blood vessels (ie, microvasculature) freeze before larger blood vessels,
and the venous system freezes before the arterial system because of lower flow
rates

19. Frostbite
Classification:
1.according to mechanism of
development:
- due
to cold air
- contact frost-bites
2. according to the depth of tissues
damage:
I degree - no symptoms of necrosis
II degree - necrosis of all layers

20. Frostbite
Course of frost-bites has 2 periods:
latent & reactive.
During latent period the patient feels cold,
paresthesia, later - anesthesia. This period
lasts up to 24 hours.
Reactive
period begins after warming the patient,
all the symptoms appear in this period.
It may be divided into 2 parts:

21. Frostbite Clinical symptoms :
I degree - moderate hyperemia & swelling, complaints of
moderate pains & feeling of burning. Healing in 5-6 days.
II degree - expressed hyperemia & swelling, the
formation of blisters with limpid liquid, complaints of
strong pains, feeling of burning, paresthesia.
Healing in 2-3 weeks.
Ill degree - expressed hyperemia & swelling, skin is
cyanotic, the formation of blisters with hemorragic liquid,
centers of necrosis, complaints of strong pains, feeling of
burning, paresthesia. Healing in 1-2 months.
IV degree - the development of dry or moist gangrene.
In absence of infection demarcation line forms in 2-3
weeks. The process may Finish with mutilation or
amputation after the formation of demarcation line.

22. Superficial Frostbite
• Includes all layers of the skin
• Initially redness in light skin, grayish in
dark skin
• Burning, tingling, itching, or cold
sensations in the affected areas, followed
by numbness
• Skin turns white, waxy; some resistance
when pressed (feels firm or “wooden” but
underlying tissue is soft); cold to the touch
• May have blistering
Photos courtesy of USACHPPM

23. Deep Frostbite
• Involves skin, muscle, tendons,
nerves, blood vessels; may include
bone
• White or yellowish waxy skin that
turns purplish blue as it thaws
• Underlying tissue hard, no resistance
when pressed, may appear
blackened and dead
• Blood-filled blisters and swelling may
develop
• May develop blood clots

24. Deep Frostbite
!!! Significant pain as affected areas re-warm; dull continuous ache
becomes throbbing sensation in 2-3 days and may last weeks to
months
!!! Frostbitten skin is highly
susceptible to infection,
and gangrene
!!! Time will reveal the final
amount of tissue damage
!!! Many people with frostbite may also
be experiencing hypothermia

25. Treatment of Frostbite
• Remove any wet or tight clothing that may cut off blood flow to
the affected area.
• Treat for hypothermia if victim is also experiencing
hypothermia. Saving their lives is more important than
preserving a finger or foot. Perform CPR if necessary.
• Do not rub the affected area, because rubbing causes
damage to the skin and tissue.
• Gently place the affected area in a warm (105°F / 40°C) water
bath and monitor the water temperature to slowly warm the
tissue. Don’t pour warm water directly on the affected area
because it will warm the tissue too fast causing tissue
damage. Warming takes
about 25-40 minutes.

26. Immersion Injury (Trench foot)
Immersion injury (trench foot) results from prolonged exposure of the feet
to wet or damp cool conditions, such as in cold water, mud, or wet fields,
or wearing damp socks. A similar condition of the hands can occur if a
person wears wet gloves for a prolonged period under cold conditions.
• Usually develops slowly, over hours to days
and at temperatures from 32°F to 50°F.
(from 0º to 10ºC)
• Can occur at temperatures as high as
60º F (15ºC) if the feet are constantly wet
• The primary injury is to nerve and muscle
tissue. There is no formation of ice crystals
in the tissues but immersion injury can
cause permanent damage.

27. Immersion Injury (Trench foot)
• Initially reddened skin, then turns pale and
mottled, finally purple, grey, or blue
• Tingling pain, itching, burning sensation,
or numbness may occur, followed by leg
cramps and swelling
• May cause permanent damage to the
circulatory system so person is more
sensitive and prone to cold-related injuries
in that area
• May develop blisters, ulcers, and
gangrene.
• Amputation may be necessary ! ! !
Symptoms
Note the cyanosis (blueness
of skin) around the nail beds;
redness and swelling; and
blisters.
PhotocourtesyofUSACHPPM

28. Immersion Injury (Trench foot)
Treatment
• Remove wet clothing and replace with dry,
warm clothing.
• Warm affected area slowly at room
temperature. Carefully clean, dry, and wrap
loosely with sterile dressing, taking care not to
break the blisters. This can lead to infection.
• Elevate feet to reduce swelling.
• Do not walk on injured feet.
• Seek prompt medical attention; trench foot can
cause severe disability.

29. Mount Everest
1996

30. I wish you do not freeze
in Ukraine !