Effect of a vapor barrier on rates of excretion of sweat solutes

Effect of a vapor barrier on rates of excretion of sEteat solutes. J. Appl. Physiol. I 4(3) : 43 I-434. 1g5g.-The effects of a vapor-im-permeable barrier on rates of excretion of Na, Cl, K, true creatinine and ‘apparent ’ creatinine from the arms of men during thermal sweating were determined by collecting sweat solutes simultaneously from both arms, one of which was en-closed in a polyethylene bag. The separate effects on rates of excretion of the higher local skin temperature (T,) and relative humidity (RH) imposed by a vapor barrier were assessed by means of a thermoregulated arm-chamber. Wearing a vapor barrier resulted in a significantly decreased rate of excretion of K and an increased rate for both true and ‘apparent ’ creatinine. The effect on ‘apparent ’ creatinine was attributable entirely to the increased excretion of the fraction represented by true creatinine. Rates of excretion of Na and Cl were not signifi