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What Is Frostbite?

Frostbite is damage to the skin and underlying tissues caused by exposure to freezing temperatures below 32 degrees Fahrenheit or 0 degrees Celsius. It can result in permanent tissue damage, including skin necrosis (tissue death). Extreme cold, windy, and wet conditions increase the risk of frostbite on exposed skin. 

What is the Difference Between Hypothermia and Frostbite?

Frostbite and hypothermia are both medical emergencies that occur as a result of exposure to cold temperatures, but they affect the body differently. 

Frostbite occurs due to a skin freeze. It causes damage to skin tissue in specific parts of the body, such as exposed skin of the hands, feet, ears, nose, and lips.

Hypothermia is a condition in which the core body temperature drops below 95°F (35°C). It affects the whole body and is a more serious condition than frostbite.

Frostbite vs Chilblains

Frostbite and chilblains are both skin conditions related to cold exposure, but they have some key differences. 

Frostbite is skin damage caused by exposure to freezing temperatures, while chilblains are caused by exposure to cold (but not freezing) temperatures. 

Chilblains (also called pernio) develop due to damage to blood vessels in the skin after being exposed to cold or damp weather. These small blood vessels under the skin get inflamed, causing painful, itchy sensation in the affected areas, where blisters may also form. Additionally, skin can appear pale, purple, red, or blue.  

Chilblains can clear up on their own within 3 weeks with home treatments while frostbite can potentially be serious and require immediate medical attention.

Causes of Frostbite

How Frostbite Occurs With Cold Exposure

The skin has as much as 75% water content. When skin is exposed to freezing temperatures, ice crystals form in the water in the skin. These extracellular ice crystals cause damage to skin cells and tissues, preventing blood flow in the affected area. Due to this reduced blood flow, severe frostbite can lead to muscle, nerve and joint damage in addition to the damaged skin.

As mentioned, frostbite develops with exposure to freezing temperatures, especially in windy or wet conditions. However, a non-freezing cold injury can develop with exposure to cold temperatures (slightly above freezing point) for prolonged periods. In addition, you can develop frostbite if a frozen object, such as an ice pack, is pressed against your skin for too long or if you have prolonged exposure to a very cold liquid, such as freezing water or wet clothing. 

While the risk of frostbite is higher if you’re not wearing enough protective clothing, frostbite can occur through cold-weather clothing such as hats, gloves, and boots. 

Vulnerable Areas in Cold Weather

Frostbite can occur in the skin in any part of your body, but exposed skin of the face and limbs is at greater risk, including:

• Hands and feet

• Fingers and toes

• Nose, ears, and lips

Environmental Conditions Leading to Frostbite

• Freezing conditions with extremely low temperatures at or below 32°F or 0°C

• Windy weather conditions

• Wet conditions

• High altitudes

Note: Frostbite can develop in under 30 minutes when the wind chill is -15°F or -26°C or below.

Other Risk Factors 

Anyone can develop frostbite with exposure to freezing temperatures. However, some people are at a higher risk of this serious cold weather condition: 

• Age: People younger than 18 years or older than 65 years.

• Occupation and Hobbies: Skiers, snowboarders, mountain climbers, rescue workers, military personnel, and outdoor plant and machine operators.

• Location: People who live in cold climates or high altitudes with windy weather conditions. 

• Social Factors: Those without housing or heat during the winter months.

• Lifestyle Factors: Smokers.

• Underlying Medical Condition: Malnutrition, peripheral vascular disease, Raynaud’s phenomenon, arthritis, diabetes, hypothyroidism (underactive thyroid gland). 

Recognizing Frostbite Symptoms: What Are The 3 Signs of Frostbite?

The signs and symptoms of frostbite depend on the stage of frostbite or the severity of skin damage that has occurred. 

Early Signs of Frostnip

Frostnip is the first stage of frostbite. Initial symptoms of frostnip may include:

• Changes in skin color from red to purple 

• Pale skin (lighter than the natural skin tone)

• Feeling cold in your skin

• Slight discomfort or pain

• Numbness and tingling 

• Chilblains (small red bumps) may develop in the affected areas of cold injuries after rewarming

Frostnip is an early warning sign and the skin damage is not permanent. However, you should see your healthcare provider even if you have mild symptoms of frostnip so that your provider can make sure there’s no long-term skin damage.

Symptoms of Superficial Frostbite

Superficial (surface) frostbite is the second stage of frostbite that affects the upper surface of the skin. Signs and symptoms of superficial frostbite may include:

• Warmth in the skin despite ice crystal formation

• Pins and needles or stinging sensation in the injured area

• Swelling

• Painful blue or purple patches similar to a bruise can develop after rewarming the skin; you may also develop peeling skin similar to a sunburn; fluid-filled blisters may form after 1-2 days

Superficial (surface) frostbite requires immediate medical evaluation and treatment. 

Signs of Deep Frostbite 

Deep frostbite is the third and most severe stage of frostbite. These frostbite injuries cause tissue damage in the deep layers of skin. Signs and symptoms of severe tissue damage may include:

• Inability to move the affected area 

• Large blisters in the frostbitten skin 1-2 days after cold exposure

• The affected skin may turn black due to necrosis (tissue death) 

• A carapace (hard, black covering) may form and fall off spontaneously or require surgical removal

Signs of a Medical Emergency: When to Seek Medical Care for Frostbite?

You should seek medical care for any suspected cold injury. Cold exposure injuries such as frostbite are extremely dangerous because they can numb your skin so you don’t feel severe pain. As a result, you may not realize the severity of your frostbite injury. That’s why it’s important to be evaluated by a healthcare provider even if you think you have mild frostbite or frostnip.

Signs of a medical emergency and severe frostbite include:

• Skin discoloration

• Numbness or lack of sensation in the affected area

• Severe pain

• Drainage of fluid from the affected skin

• Skin color and sensation do not return after rewarming at home for mild frostbite

• New symptoms, such as fever or malaise (a general feeling of being unwell)

Treatment of Frostbite

Immediate First Aid Steps: How Do You Get Rid of Frostbite?

• Immediately seek shelter from freezing temperatures if you notice frostbite symptoms.

• Remove wet clothing and put on dry clothing. Be gentle when removing cold weather gear such as hats, scarves, gloves, and boots. Also remove any jewelry from the affected area. 

• Thaw the affected skin with warm (but never hot) water to prevent further damage. This is a slow process and should take at least 30 minutes.

• Warm your whole body with a warm blanket or warm bath (make sure the water is lukewarm, not hot). Do not wrap blankets too tightly around your body as this might cut off circulation. 

• Do not apply direct heat to affected skin (this may cause burns).

Will Frostbite Heal On Its Own?

The first stage of frostbite (frostnip) can heal on its own with home treatment. However, it’s best to be evaluated by a healthcare professional to ensure there is no permanent damage.

If you are unable to access medical care immediately:

• Find shelter and try to stay warm. 

• Remove wet clothing and change into dry clothing. 

• Thaw or rewarm the affected area in warm water.

• Cover the frostbitten area with clean clothing. Wrap each finger and toe separately to avoid friction damage. 

• Avoid stress or pressure on the injured area.

• Avoid tightly wrapping the frostbitten area as this can cut off circulation. 

• Avoid walking on frostbitten feet.

• Take over-the-counter pain relievers for pain control.

Medical Treatment Options

You should see your healthcare provider or go to the emergency room immediately for symptoms of superficial or deep frostbite (the second and third stages). Remember, time is critical when treating frostbite to prevent further damage. Options to treat frostbite may include:

• Slowly raising your body temperature with the application of warm packs

• Dressing the frostbitten area with sterile bandages and keeping your fingers and toes separate to prevent them from rubbing against each other 

• IV fluids for rehydration

• Antibiotics

• Medications for pain control

• Oxygen therapy for severe frostbite. This is called hyperbaric oxygen therapy and can help damaged tissues heal faster by raising blood oxygen levels.

• Studies to evaluate blood flow in the area of frostbite injury

• Technetium 99 bone scan to assess the severity of the cold weather injury

Surgical Treatment of Frostbite

Severe cases of frostbite may need surgical treatment to remove dead tissue. These procedures on affected tissues may be done several weeks or months later since your doctor needs to wait and see if the damaged tissue needs to be removed surgically and how much of the tissues need to be removed. Your doctor may decide to amputate the finger(s) or toe(s) if you develop complications such as gangrene, also called “gangrenous necrosis,” where the body tissue dies due to a lack of blood flow or bacterial infection. In the case of frostbite, gangrene can happen due to the lack of blood flow. 

Keep in mind that tissue death may be so severe with frostbite that autoamputation may occur where the affected body tissues or parts detach spontaneously. 

Long-Term Care and Recovery 

Long-term care and recovery from frostbite will depend on the extent of skin damage and whether you have any irreversible tissue damage. Clear fluid-filled blisters are a sign of temporary skin damage. Blackening or darkening of the skin and blood-filled blisters indicate more severe or permanent skin damage. 

Tips for Prevention of Frostbite

• Avoid going outdoors in freezing conditions.

• Avoid prolonged exposure to very cold temperatures. Limit the amount of time you spend outside to 10-15 minutes at most when it’s cold out.

• Dress in appropriate clothing before heading out in cold temperatures, including layers, warm socks and boots, a thick hat, gloves, and a scarf to cover exposed skin.

• Choose waterproof and windproof cold-weather gear.

• Make sure your clothes and boots are not too tight as this can cut off circulation and lead to poor blood flow in frostbitten feet, hands, and other parts of the body. 

• Keep moving when outside in cold weather to keep your blood flowing.

• Carry your phone with you so you can call for help.

• Keep an emergency kit in your car, including food, water, a first aid box, and some extra gloves, boots, and blankets.