frostbite
The effect of severe cold on the body's most exposed parts, most commonly affecting feet, hands, ears, nose. Tissues freeze, and the damage depends on the scale and duration of the exposure. In mild cases, if thawing is not long delayed, only the superficial layers freeze; injured skin is shed and replaced by new growth. Deeper tissues — muscle, bone, and tendon — may suffer in more severe frostbite, and cell damage may be irreversible. Damage to nerves may cause permanent sensory loss. Damage to blood vessels makes them leaky so that restoration of the circulation during thawing leads to escape of fluid into the tissues, hence oedema and viscosity of the blood, and obstruction of the local circulation, sometimes leading to gangrene and loss of the affected part.
— Stuart Judge
See cold exposure.
