Sauna, shower, and ice water immersion. Physiological responses to brief exposures to heat, cool, and cold. Part I. Body fluid balance.

Nine men were subjected to four temperature exposures to detect changes in weight, hemoglobin, hematocrit, and relative volumes of plasma. The exposures were: (A) sauna and head-out ice water immersion; (B) sauna and 15 degrees C shower; (C) sauna and room temperature; (D) head-out ice water immersion and room temperature. All experiments were repeated and ended with recovery at room temperature. The greatest weight loss (mean +/- S.D.) (i.e. sweating) was observed in C, 544 +/- 207 g. The weight losses (mean +/- S.D.) in A and B were equal, 417 +/- 253 g and 437 +/- 221 g. The relative post-exposure plasma volumes decreased 7.2% in A, 8.0% in B, and 5.6% in C; the decrease in D (1.3%) was statistically not significant. Combinations of heat and cold or cool (A and B) reduced the plasma volumes more than mere heat (C), suggesting a disturbance of cutaneous circulation producing transient edema in the skin.