Experimental Frostbite. Effect of Brief Freezing and Burning on Tissue Loss Following Standard Frostbite in the Rat

¹ From the Department of Physiology, School of Medicine, Stanford University, Stanford, California

Tissue loss in rat feet following standard frostbite (–25°C for the time necessary to freeze plus 15 or 30 sec.) was determined in control animals and in animals which had had one foot injured by brief freezing (–25°C for 1 sec.) or brief burning (+48°C for 135 sec.) two days earlier. Brief freezing of one foot decreased tissue loss resulting from subsequent standard frostbite of the same foot. The same effect was found in adrenalectomized rats. Brief freezing of one foot did not decrease tissue loss resulting from later standard frostbite of the contralateral foot. Brief burning decreased tissue loss resulting from later 15-second frostbite of the same foot. Brief freezing of a rat foot produced increased skin temperature of that foot, and the temperature was still elevated at the time of standard frostbite 2 days later.