In frost bite, skin becomes hard black in about :
High-Yield Explanation
C i.e. 2 weeks Trench (immersion) foot results from prolonged exposure to severe cold (5 -8degc) of dampness. Frost bite occurs d/t exposure to greater extremes of cold (-2.5degc), develops more rapidly, & may affect other pas such as nose, ears. Skin becomes hard & black in 2 weeksQ (after initial blanching & paleness erythema & edema bisters).