Synchronisation of Cold Induced Vasodilation in the Fingers of Two Immersed Hands

Abstract : In an attempt to quantify the contribution of central and peripheral mechanisms to blood flow in the hands during immersion in cold water, eight male subjects immersed their hands simultaneously (S) and five minutes after each other (NS) in water of 10 degrees C. Starting 15 minutes after immersion of the first hand, a period of 32 minutes was used for an analysis of the temperature fluctuations on all finger tips. The mean Pearson Correlation Coefficient (PCC) of all combinations of finger temperatures was taken as an indicator for the amount of central/local influence. The PCC did not differ between S and NS. The mean PCC was 0.63, which implied a greater central influence than in a previous investigation (Daanen and Lotens, 1992), in which the body heat content and water temperature was lower (PCC = 0.55). The substantial central influence was also shown by the variation in heat transfer of the hands to the water, which was 43% of the average fluctuation in finger temperature and only 31% in the previous investigation. It is supposed that central heat elimination is predominant when the core temperature surpasses a subject specific threshold, and that its influence decreases when core temperature and water temperature decreases.