Frostbite is a localized form of tissue necrosis caused by exposure to cold. It occurs when body tissues freeze due to prolonged exposure to subzero temperatures (below 0 °C). As a result of the cold, peripheral vasoconstriction develops, regional blood flow slows down, and oxygenation decreases. At the cellular level, metabolism slows, intracellular fluids crystallize, causing physical tears in cell membranes, which leads to tissue disruption. In advanced stages, this process can result in irreversible tissue death, i.e., necrosis. Environmental factors such as humidity, wind, and prolonged exposure to open air accelerate the onset of frostbite.

Frostbite most commonly affects areas with weak peripheral circulation such as the hands, feet, nose tip, ears, and cheeks. The severity of the damage varies based on exposure duration, environmental conditions, the individual's systemic condition, and the protective quality of clothing.

Risk Factors

The risk of developing frostbite increases with a combination of individual and environmental factors. The main risk factors include:

• Prolonged exposure to extremely cold, wet, and windy conditions
• Wearing wet or sweaty clothing outdoors
• Wearing tight footwear or gloves that restrict circulation
• Smoking, which causes peripheral vasoconstriction
• Alcohol use, malnutrition, altered mental status, or sleepiness
• Circulatory disorders such as diabetes, arterial diseases, or peripheral neuropathy
• Limited mobility due to old age, childhood, or disability

These factors impair the body's ability to maintain heat and facilitate localized freezing.

Clinical Classification and Symptom Levels

Frostbite is classified into three degrees based on the depth of tissue damage:

First-Degree (Superficial Frostbite)

This is the mildest form. The skin appears pale, cold, and firm. Symptoms include numbness, tingling, and a pricking sensation. Following reperfusion, erythema, swelling, and pain may develop. Permanent tissue damage is rare and recovery is generally spontaneous.

Second-Degree (Deeper Superficial Frostbite)

Affected areas exhibit swelling, erythema, and fluid-filled blisters. These blisters are susceptible to infection. The deep dermal layers are affected. Healing often involves crusting, pigment changes, and persistent pain.

Third-Degree (Deep Frostbite)

Characterized by advanced tissue necrosis. The skin turns black and dry gangrene may occur. Numbness (anesthesia) is typical. Necrotic areas are clearly distinguishable from healthy tissue. Surgical debridement and often amputation are required. The risk of sepsis and systemic complications is high.

^{First-Degree Frostbite (Ministry of National Education, Emergency Health Services)}

Pathophysiological Process and Complications

Frostbite, if not treated promptly, progresses in severity. Tissue ischemia, cell membrane disruption, intracellular ice crystal formation, and reperfusion injury complicate the condition. The main complications include:

• Sensory loss and motor dysfunction due to nerve and vascular damage
• Deep soft tissue loss (tendon, muscle)
• Secondary bacterial infections
• Gangrene, osteomyelitis, and sepsis
• Long-term joint stiffness and limited mobility

The healing process may take several weeks in mild cases and months in severe ones. A significant portion of third-degree cases requires surgical intervention.

^{Third-Degree Frostbite (Ministry of National Education, Emergency Health Services)}

First Aid Measures

Timely and appropriate first aid in frostbite is critical to limiting the depth of tissue damage:

• The patient should be immediately removed from the cold environment and brought into a warm setting of 20–25 °C (68–77 °F).
• Wet, frozen, or tight clothing should be removed and replaced with dry, insulating garments.
• The affected area should never be rubbed or massaged, as this can cause microvascular tears.
• The frozen extremity should be kept in a natural position and not forced.
• If conscious, the patient can be given warm, sugar-free, non-alcoholic fluids to support systemic warming.
• Blisters should not be popped; instead, they should be covered with sterile dressings to reduce infection risk.
• The affected area should not be exposed to direct heat sources such as stoves, radiators, electric blankets, or hot water bottles.
• Professional medical help should be obtained as soon as possible.

Medical Treatment and Management

Medical intervention is determined by the degree of frostbite and the patient's overall condition:

• Tissue perfusion is assessed through imaging techniques (e.g., thermal cameras, Doppler ultrasound).
• In mild cases, topical antibacterial agents, pain management, and moist wound care may be sufficient.
• In moderate to severe cases:
• Intravenous fluid therapy supports circulation.
• Necrotic tissues are removed through debridement.
• If infection develops, systemic antibiotic therapy is administered.
• Pain relief and limb-preserving methods (e.g., hyperbaric oxygen therapy—considered experimental) are evaluated.
• Amputation is performed if necessary.

Long-term recovery may involve physical therapy, sensory-motor rehabilitation, and psychosocial support.

Preventive Strategies

The following precautions can reduce the risk of frostbite:

• Wear multilayered, waterproof, windproof clothing.
• Use peripheral protective gear such as gloves, socks, hats, and face masks.
• Perform periodic movement and exercises to improve circulation.
• Limit alcohol and nicotine consumption.
• Avoid being alone in high-risk cold environments and routinely inspect body parts.
• Provide warming breaks for individuals who must work outdoors for extended periods.