Heat balance at -5 degrees C after cold water immersion

Two different possible behaviors at -5 degrees C after cold water immersion were studied. A test subject wearing winter clothing walked (5 km/h) on a treadmill for 45 minutes at -5 degrees C and at a wind velocity of 3 m/s with dry clothing, immediately after a thorough immersion in 5 degrees C water, or after immersion and wringing, freezing, and beating of the clothing (to remove ice). A marked heat debt (ca. 1000 kJ) was measured at the end of the cold water immersion. Attempts to dry the clothing caused an additional heat debt of ca. 300 kJ. After 45 minutes walking, the difference in heat depth between the treatments was nearly the same as before the exercise. The difference in clothing weight was only 0.9 kg between the two treatments after walking. Beating frozen clothing items could remove ice corresponding to only 0.7% of the wet weight of the clothing. Results suggest that after cold water immersion in winter, the undressing procedure could not be recommended. Instead, after initially removing boots, mittens, and hat, the subject should start walking. The water accumulated in boots and mittens should be poured out when necessary.