What is frostbite?

Frostbite is characterized as a localized injury that occurs when skin and underlying tissues freeze due to extreme cold exposure. This condition typically affects extremities such as fingers, toes, earlobes, and the nose, where blood circulation may be reduced during colder temperatures. The freezing process leads to damage of the skin and can result in necrosis if not treated properly. Recognizing frostbite is essential in cold weather conditions, and timely intervention can significantly reduce the likelihood of severe tissue damage.

In this context, the other options do not accurately define frostbite. Severe burning injuries and localized injuries from overexposure to heat relate to thermal burns, which are caused by heat rather than cold. A response to high altitude is typically associated with conditions like altitude sickness, which is not relevant to frostbite. Hence, the definition of localized injury due to overexposure to cold is the correct focus for understanding frostbite.