Fluid Replacement and Heat Stress, 1993
Pp. 143-160. Washington, D.C.
National Academy Press
Hiroshi Nose, Gary W. Mack, Xiangrong Shi, and Ethan R. Nadel1
Humans have a prolonged period of delayed rehydration after thermal dehydration. This phenomenon has been known as involuntary dehydration since 1974 (Rothstein et al., 1947), and a number of studies have been conducted to better understand its cause (Greenleaf and Sargent, 1965; Greenleaf et al., 1983; Mack et al., 1986). Dill et al. (1933) suggested that thirst is primarily a function of the sodium chloride concentration in plasma rather than plasma volume. Greenleaf (1982) stated that two factors unique to humans contribute to the involuntary dehydration: excessive extracellular fluid loss due to Na+ loss into sweat and the upright posture. Recently, Morimoto et al. (1981b) found that the degree of involuntary dehydration in humans was reduced when a glucose-electrolyte solution rather than water was ingested during thermal dehydration. However, their results may have
Hiroshi Nose, Foundation Laboratory and Departments of Epidemiology and Public Health and Physiology, Yale University School of Medicine, New Haven, CT 06519