Which term is defined as a freezing injury to tissues?

• A. Frostnip
• B. Frostbite
• C. Trench Foot
• D. Hyperthermia

Answer: (B)

Freezing injury to tissues is frostbite. When tissue temperatures drop below freezing, ice crystals form in the tissue and in the small blood vessels, causing cellular damage and vascular injury. This is what frostbite describes—tissue damage from actual freezing, potentially ranging from superficial skin and subcutaneous tissue to deeper structures in more severe cases.

Frostnip, in contrast, is a milder, surface-level freezing that doesn’t involve tissue freezing or lasting damage. Trench foot stems from prolonged exposure to cold, wet conditions and is a non-freezing ischemic injury from sustained vasoconstriction and poor perfusion. Hyperthermia refers to an abnormally high body temperature, not a freezing injury.