Degrees of Frostbite Injury

white to yellow firm plaque

first

no tissue loss but causalgia pain may follow

superficial blisters containing clear or milky fluid with or without erythema and edema in surrounding tissue

second

limited superficial skin loss may occur

deeper blisters containing red or purple fluid, OR darkly discolored skin without blisters

third

varies with depth of injury

extensive dark and cyanotic skin without blisters or edema

fourth

gangrene within a few hours