This document discusses frostbite, including its causes, symptoms, classification, treatment, and prevention. Frostbite occurs when skin and underlying tissues are exposed to subfreezing temperatures, causing damage from ice crystal formation and reduced blood flow. It most commonly affects the hands, feet, ears and face. Treatment involves rapid rewarming in warm water followed by wound care. Frostbite severity is classified into four stages based on depth of tissue damage. Prevention focuses on proper clothing, avoiding dehydration/exhaustion, and limiting time in extreme cold or wet conditions.

1. FROST BITE
Dr. Usha (PT)
Assistant Professor

2. • Frostbite is a freezing, cold thermal injury, which occurs when tissues
are exposed to temperatures below their freezing point (typically
−0.55°C, but can occur as high as 2°C) for a sustained period of
time[1].
Mechanism
• With low skin temperature and dehydration, cutaneous blood vessels
constrict and limit circulation because the viscosity of blood increases.
• Water is drawn out of the cells and ice crystals cause mechanical
destruction of skin and subcutaneous tissues.

3. Areas affected with Frostbite
• The areas likely to suffer from frostbite are exposed skin with little
underlying metabolically active muscle tissue.
• It most commonly occurs in the periphery. Anatomically, the hands
and feet account for 90% of reported injuries (with the fingers and toes
being most affected).
• Frostbite can also affect the face (tip of the nose, chin, earlobes, tissues
of cheeks and lips), buttocks/perineum (from sitting on metal seats)
and penis (joggers and Nordic skiers).

4. • The environmental temperature and exposure time required for tissue
to freeze will vary but when exercising temperatures must be well
below freezing point (−20°C). When tissue is frozen, blood flow will
cease and the tissue will become hypoxic.
• If not treated quickly by a slow re-warming process, tissue can further
break down leading to gangrene and eventually amputation is the only
course of action to prevent further complications including death. The
key is that in its early stage frostbite is reversible so medical attention
and treatment must be sought quickly.

5. • Severity of injury depends on factors such as
Absolute temperature,
Wind chill,
Duration of exposure,
Wet/dry cold,
Immersion,
Clothing quality and
Patient comorbidities such as smoking, peripheral vascular disease,
neuropathies, Raynaud's disease, mental health issues, substance abuse and
dementia.
• Alcohol consumption is potentially particularly devastating as it causes heat loss
through peripheral vasodilatation and also impairs judgement.
• This may affect the individual's ability to seek adequate shelter, compounding the
injury.

6. Clinical Features
Frostbite can be broadly classified as:
• Superficial or mild, involving the skin and subcutaneous tissue only,
or
• Deep or severe, involving the full skin thickness and deeper tissues.

7. Patients with superficial frostbite
• Complain of a burning local pain with numbness.
• On examination, the skin is initially pale and grey and becomes red after
thawing.
• Superficial serous bullae (blisters) may be present; haemorrhagic blisters
represent sub dermal damage.
• Local thawing by contact with direct body heat can treat superficial
frostbite.
The injured part should not be directly rubbed as sloughing may occur. No
attempt should be made to thaw the injured part unless it is certain that
refreezing will be prevented. Refreezing results in a far more serious injury.

8. Deep Frostbite
• It is initially extremely painful and then becomes numb. The body part
affected appears as a frozen block of hard, white tissue with areas of
gangrene and deep hemoserous blisters if severe.
• The affected part should be rapidly rewarmed in a hot water bath of
temperature 39–41°C (102–106°F).
• A whirlpool bath with added antiseptic is ideal. The rewarming
process is often acutely painful and requires analgesia.
Radiant heat from a fire or radiator should not be used as skin burns
may occur. The tissue should continue to be warmed until it becomes
soft and pliable and normal sensation returns.

9. • Appropriate tetanus prophylaxis is indicated. The serous blisters
contain thromboxane's and prostaglandins that damage underlying
tissue. These serous blisters should be debrided and treated topically
with aloe.
• Haemorrhagic blisters should be left intact. Ibuprofen 400 mg orally
twice a day is recommended to prevent further prostaglandin-mediated
tissue damage.

10. • Intravenous infusion of low-molecular-weight dextran may help
reduce swelling and maintain vasodilatation.
• Prophylactic parenteral penicillin should be administered for 72 hours.
It is important to salvage as much tissue as possible.
• Debridement should be delayed for days to weeks when obvious
demarcation has occurred. Contractures and compartment syndromes
may develop and should be treated appropriately.

11. • Further, Frost bite has been divided into four categories of severity,
analogous to burn injuries. These are only recognisable upon
rewarming.

12. Stages of Frost Bite
STAGES FEATURES RECOVERY
First Degree Frost Bite
(Frostnip)
Presents with erythema, oedema, cutaneous
anaesthesia and transient pain
Full recovery is expected, with only mild
desquamation
Second Degree Frost Bite Characterised by marked hyperaemia, oedema
and blistering with clear fluid in the bullae
Healing occurs, but many patients have long
term sensory neuropathy, often with significant
cold sensitivity
Third Degree Frost Bite Consists of full thickness dermal loss, with
haemorrhagic bulla formation or development
of waxy, dry, mummified skin
The later features are poor prognostic indicators
for tissue loss
Fourth Degree Frost Bite Full thickness loss of the entire part, with skin,
muscle, tendon and bone damage
Injuries of this severity leads to amputation

15. Treatment
Fundamental therapeutic goals in frost bite are:
1. Rapid rewarming
2. Prevention of further cold exposure
3. Restoration of circulation

16. • Once the patient is in a sitting in which refreezing can not
occur rapid water bath rewarming is indicated. The water
bath temperature should be about 37-39 degree C (99-102
degree F)
• Rubbing the frozen extremity with ice, using dry heat, and
slow rewarming are all contraindicated
• In the hypothermic patient with frostbite injury, it is
important to complete fluid resuscitation and core rewarming
before limb rewarming, to prevent sudden hypotension and
shock

17. • Routine wound care, protection of the frostbitten part, and tetanus
prophylaxis is should then follow
• Radiologic evaluation (MRI, bone scan, plain films) may help
determine extent of injury and prognosis
• Nowadays, triple- phase bone scans and considered the standard of
care for assessing tissue viability during the initial days following
injury
• Because of increased blood viscosity, sludging, thrombolytic therapy
(e.g. Heparin, Streptokinase) has been suggested

18. • Superficial white (non haemorrhagic) bullae may be debrided
to avoid prolonged exposure to prostaglandins and
thromboxane in blister fluid
• Aloe Vera, a thromboxane inhibitor, has been shown to be
useful as a topical agent in superficial frost bite

19. Prevention of cold injuries
The majority of cold injuries are preventable if general
guidelines are followed and the athlete benefits from the
specific strategies that have been developed for cold weather
activities.

20. General guidelines
The following guidelines apply to all activities where hypothermia has the potential
to occur:
• Plan adequately and Communicate plans to others.
• Avoid activity inappropriate for fitness level.
• Avoid activity to exhaustion.
• Avoid dehydration.
• Ensure adequate nutrition.
• Warm up appropriately.
• Wear appropriate clothing for weather conditions.
• Cancel activity or seek shelter if appropriate.
Note that the American College of Sports Medicine recommends that if the
ambient dry bulb temperature is below –20°C (–4°F), race directors should
consider cancelling or rescheduling races.

21. • Athletes should wear appropriate clothing for the particular
environmental conditions. It is advisable to wear a number of layers of
clothing rather than one thick layer.
• This will enable the athlete to remove layers of clothing when
exercising in warmer conditions and therefore reduce sweating. It also
enables the athlete to put on additional clothing if the temperature or
level of activity drops.
• Clothing should be made of a good insulating material such as wool,
synthetic fleece or polypropylene. Use of cotton garments should be
avoided.

22. • In rain or snow, adequate waterproof outer clothing should
be worn. The outer jacket should also offer adequate
protection against wind. Recommended materials include
nylon and Gore-Tex.
• In cold conditions, extremities such as the head, face and
hands should be covered. Synthetic or wool socks should be
worn instead of cotton.

23. Running and cycling
• Runners and cyclists are at particular risk of cold injuries
because they usually wear a minimum of clothing, are
exposed to an increased wind chill factor and often prefer to
train alone.
• Dehydration and exhaustion are also common.
• It is possible to see cold and heat injuries in these endurance
events.
• Slower participants are susceptible to cold injuries.

24. Mountaineers, hikers and cavers
• These athletes are at particular risk of hypothermia due to increased
convective and conductive heat loss.
• Often, when exercising in a group, the least fit person is at risk of
developing cold injuries.
• This person may have excessive sweating, hyperventilation and
peripheral vasodilatation resulting in exhaustion, dehydration and
increased heat loss.
• It is important for other members of the party to observe for the early
signs of cold injury (e.g. shivering, dysarthria, delayed cerebration).

25. Back-country and cross-country skiing
• The cross-country skier is at a high risk of cold injury due to exposure
to a cold environment and the potential for fatigue and injury.
• Clothing with effective thermal insulation including leg covers is
essential.
• It is important to keep the inner garments dry. If clothing becomes wet,
it should be changed promptly while the individual is still alert.
• The cross-country skier should never ski alone.

26. Water sports
• In surface water sports (e.g. windsurfing, kayaking), wind and spray
may contribute to cold injuries. Exhaustion may occur quickly and the
windsurfer may be some distance from shore when this occurs.
• Cold injuries can be prevented by the use of wetsuits with coverings
for extremities (e.g. hood, gloves, boots). Knowledge of weather
conditions is important and the sport should not be performed alone.
• Divers should also always dive with a partner. The dive should be
planned taking into consideration the water temperature and the degree
of insulation provided by the wetsuits.

27. Thank You