What Is Frostbite

Frostbite is a condition that occurs when skin and underlying tissues freeze mainly due to prolonged exposure to extremely low temperatures, particularly below 0 degrees Celsius (32 degrees Fahrenheit).

Read on to learn about the three different stages of frostbite, the symptoms of each, how to treat each stage, when frostbite becomes a serious threat, whether you are at risk of developing frostbite, and much more! 

Introduction 

According to Cleveland Clinic,¹ frostbite is a common form of skin injury or damage that is caused by prolonged exposure to extremely low temperatures, particularly below 0 degrees Celsius (32 degrees Fahrenheit). 

Frostbite can affect all areas of the skin, but mainly the extremities, including the hands and fingers, feet and toes, face, nose, and ears. 

Causes

As discussed above, frostbite is mainly caused¹ by prolonged exposure to extremely low temperatures (‘’freezing temperatures’’). However, frostbite can also occur due to:

• Direct contact with frozen objects: like ice or metal, for example 
• Wearing insufficient clothing: it is important to bear in mind, that frostbite can also occur when protective clothing is worn. That is why it is essential to remove any wet clothing as soon as possible

Under any of the three conditions discussed above, blood vessels constrict, which prevents blood from reaching the skin and tissues found in the extremities. As a result, the water within the skin and tissues freezes and crystallises, leading to skin and tissue damage and eventually, frostbite. 

Risk factors

Certain risk factors increase the risk of developing frostbite including:^1,2

• Age: it is suggested that people under 18 years of age and over 65 years of age are more susceptible to frostbite as their bodies tend to be less efficient in producing and retaining heat 
• Certain medical conditions: e.g. diabetes, hypothyroidism, arthritis, peripheral vascular disease, malnutrition, and Raynaud’s syndrome
• Mental illness 
• Smoking
• Alcohol and/or drug use
• Living and/or working in cold climates
• Living and/or working in places with high altitudes: places with high altitudes tend to be low in oxygen which not only increase the risk of developing frostbite but necrosis (permanent tissue death) as well
• Previous history of frostbite or cold injury
• Not having access to housing 
• Not having access to warm, protective clothes 

Signs and symptoms

The signs and symptoms¹ of frostbite vary depending on its severity and the stage at which frostbite has progressed to. 

The three main stages of frostbite include: 

1. Frostnip: the most common signs and symptoms include:
   • Cold, sore, tingly, and/or painful skin 
   • Red or purple skin 
   • Small red bumps (chilblains) may develop on the skin 
2. Superficial (surface) frostbite: the most common signs and symptoms include:
   • Warm skin
   • Pins and needles
   • Purple or blue skin: appears like a bruise
   • Peeling skin: feels like a sunburn

Blisters may develop on the skin: if the blisters are clear, this could be a sign of temporary skin damage. If fluid-filled or blood-filled, however, they could be a sign of permanent skin damage.

This stage of frostbite requires medical treatment. 

3. Severe (deep) frostbite: the most common signs and symptoms include:
   • Total numbness (non-feeling): this occurs due to freezing of the lowest tissue layer (subcutaneous tissue) 
   • Difficulty moving frostbitten areas: due to numbness
   • Large, fluid-filled blisters: these may form on the skin one to two days following cold exposure
   • Hard, black skin (‘’carapace’’) that often falls off on its own: due to skin cells dying after freezing. This is a sign of severe tissue damage

This stage of frostbite requires immediate medical attention. Otherwise, permanent damage to muscles, nerves, and/or joints may occur, eventually leading to the development of gangrene, necrosis, and/or secondary infections. 

Diagnosis

A healthcare provider will provide a diagnosis¹ for a suspected patient with frostbite by performing a series of tests in the following order: 

1. Medical history and physical examination: during the physical examination, the healthcare provider will look for signs of skin discolouration or skin symptoms such as blisters or mottling (blotchy, red-purplish skin) 
2. Imaging tests: 
   • X-ray (radiography): a type of imaging test that uses electromagnetic radiation to take pictures of bones and soft tissues in the body. The healthcare provider may use it to check for signs of tissue damage beneath the skin

Management and treatment options

The management and treatment¹ for frostbite depend on which stage the frostbite has progressed to. 

Frostnip

To treat frostnip, adhere to the following steps:

• Get out of the cold and seek shelter as soon as possible
• Remove all wet and cold clothing, including hats, gloves, and boots
• Remove any jewelry, including rings or watches
• Take a warm (not hot) bath for approximately 30 minutes: make sure to keep the affected areas saturated in the warm water 
• Cover yourself in a warm blanket: make sure not to wrap it too tightly around you as this can further restrict blood flow to affected areas and do more harm than good

Surface or deep frostbite 

If you develop either surface or deep frostbite, seek medical treatment immediately. 

To treat surface or deep frostbite,¹ a healthcare provider will: 

• Warm up the affected skin by immersing it in warm (not hot) water and/or applying warm, wet packs to it for approximately 30 minutes 
• Clean up the frostbitten skin and wrap it up in sterile bandages: to avoid infection
• Insert an intravenous (IV) needle with fluids into the vein of the patient’s arm to improve circulation: this is particularly performed when patients develop stage three (deep) frostbite
• Provide the patient with pain-relieving medication: such as ibuprofen and/or antibiotics
• Provide the patient with water: to rehydrate the patient’s dehydrated frostbitten tissues
• Use ‘’hyperbaric oxygen therapy’’ to restore blood-oxygen levels and promote tissue healing: the treatment involves exposing patients with extreme frostbite to a pressurised room filled with pure oxygen 

In severe cases, patients may be required to undergo surgery in order to remove any dead skin or tissues. If the patient has developed gangrene due to tissue death, the extremities, including the fingers or toes, may need to be amputated (cut off) by a surgeon. 

Complications 

If frostbite is left to progress past the first (frostnip) stage due to lack of and/or improper treatment, it can lead to a wide range of severe complications¹ including: 

• Nerve damage (neuropathy)
• Excessive sweating (hyperhidrosis)
• Arthritis and stiffness in hands and feet
• Increased sensitivity to the cold
• Skin discoloration
• Scarring
• Nail loss or nail damage
• Gangrene (tissue death) 
• Secondary infections
• Amputation (surgical limb removal)
• Muscle, bone, and/or tendon damage 

When to see a doctor 

Seek immediate medical attention² if you: 

• Develop signs and symptoms of surface or deep frostbite
• Develop new, unexplained symptoms 
• Experience pain, swelling, inflammation, and/or discharge in the frostbitten area(s)
• Experience fever 

Seek immediate emergency care² if you:

• Develop hard, cold, blotchy skin 
• Suspect or experience hypothermia (low body temperature): hypothermia is characterised by:
  • Intense shivering
  • Slurred speech
  • Drowsiness
  • Decreased coordination

Summary 

Frostbite is a common form of skin and tissue damage mainly caused by prolonged exposure to freezing temperatures below 0 degrees Celsius (32 degrees Fahrenheit). 

Frostbite affects people of all ages, but predominantly people aged under 18 and over 65 years of age. People with certain medical conditions (e.g. diabetes), no housing, jobs in cold climates with high altitudes (low oxygen), a previous history of frostbite, smoking, alcohol, and/or drug use are also deemed to be high risk. 

The signs and symptoms of frostbite depend primarily on the stage the frostbite has progressed into. 

Frostbite has three main stages:

1. Frostnip: mild form that is mainly characterised by cold, sore, and painful red-purplish skin
2. Superficial (surface) frostbite: results in temporary skin damage and is mainly characterised by blisters, and purplish-blue, spotty, peeling skin 
3. Severe (deep) frostbite: results in permanent skin and tissue damage (necrosis) if left untreated. Mainly causes numbness, and fluid-filled blisters

At present, frostbite is mainly diagnosed via a physical examination and X-ray imaging test.

Management and treatment depends on the stage of frostbite but primarily involves:

• Getting out of the cold and seeking shelter as soon as possible
• Warming up affected skin as soon as possible for approximately 30 minutes 
• Removing wet clothes as soon as possible 

Surgery with the possibility of amputation, hyperbaric oxygen therapy, and/or IV injections may be used to treat severe and extreme cases of frostbite.

See a doctor or visit an emergency room immediately if you develop:

• Signs and symptoms of superficial (surface) or severe (deep) frostbite
• Hypothermia, fever, and/or pain, swelling, or discharge in the frostbitten areas 
• Cold, hard, blotchy skin