Frostbite freezes living tissue, often after milder frostnip
When skin or deeper tissue actually freezes—especially fingers, toes, nose, ears, cheeks, and chin—frostbite begins, frequently after frostnip's pale or red warning. Mountaineers may see yearly rates near forty percent, and Andean mummy evidence pushes human cases back some five thousand years.
Frostbite injures living tissue that has been allowed to freeze, most often on fingers, toes, and exposed facial skin. Long cold exposure raises risk for winter athletes, soldiers, and people without housing; alcohol, smoking, mental illness, some drugs, and earlier cold injury add vulnerability. Prevention means covering clothing, steering clear of wind and extreme cold, staying fed and hydrated, and moving enough to hold core heat without exhausting reserves. Clinicians rewarm with immersion near body heat or shared body warmth, and only when refreezing is unlikely.
Historical grading borrows burn language. First-degree injury stays superficial and usually leaves no permanent damage: early numbness, waxy swollen skin, and a red border. Second-degree cases form clear blisters and a hardened surface that later dries, darkens, and peels away. Deeper grades bring lasting pain and black eschar; fourth-degree frostbite reaches muscle, tendon, or bone, with colorless hard skin and oddly painless early rewarming. Cheeks, ears, nose, and digits remain classic sites as symptoms advance with time in the cold.
Documented human frostbite reaches about five thousand years, including a pre-Columbian Andean mummy. Global yearly case totals are unknown, yet among mountaineers rates may approach forty percent annually. Cold still outranks many modern hazards for people who work or sleep outdoors: the biology is simple freezing, but the social pattern tracks who cannot leave the cold—and who meets frostnip's pale or red warning before deeper injury sets in.
Source: Frostbite
