Frostbite is a localized injury resulting from freezing of the skin and underlying tissues, typically caused by exposure to extreme cold. The process involves the formation of ice crystals within body fluids and the resulting vasoconstriction, which severely limits blood flow and oxygen delivery to the affected area. Tissue damage occurs due to a combination of freezing injury, secondary reperfusion injury when circulation is restored, and the toxic effects of ice crystal formation. Severity ranges from superficial damage, such as frostnip, which affects only the outer layers of skin, to deep tissue necrosis, which may require surgical intervention to remove dead tissue. Management focuses on rewarming the affected site, restoring local circulation, and preventing severe infection.