Rapid Acclimatization to Work in Hot Climates

Heat acclimation: Gold mines and genes

“…The 4 classic signs of heat acclimation were considered: a reduced core temperature, reduced skin temperatures, reduced heart rate, and increased sweating for a given level of exercise and heat exposure. 27 Eichna et al reported similar physiological changes during acclimation to a hot and humid environment. 28 Additional early markers of heat acclimation include reduced electrolyte losses in sweat and an expanded plasma volume which was believed to contribute to the reduced heart rate.…”

“…Dill and colleagues in 1933 also noted a progressive increase in sweat rate and reduction in sweat chloride concentration which they attributed as signs of heat acclimation. 26 In the 1940s Sid Robinson and coworkers 27 developed what we now consider the "traditional protocol" for artificial heat acclimation. His subjects were exposed to a pre-determined hot climate and moderate exercise, at approximately 50% of maximum oxygen consumption.…”

Heat Acclimatization in Hot Summer for Ten Weeks Suppress the Sensitivity of Sweating in Response to Iontophoretically-administered Acetylcholine

“…In unacclimatized individuals, exposure to hot ambient conditions causes a high core temperature and an increased heart rate (Robinson et al, 1953;Wilkerson et al, 1986). However, prior heat exposure for lasting several consecutive days, improves heat resistance (Sato & Sato, 1983;Sato et al, 1990;Nielsen, 1998) by increasing sweat output, lowering the heart rate, and slowing the rise in the core temperature (Wyndham, 1967;Nadel et al, 1974;Ogawa & Sugenoya, 1993;Nielsen, 1998).…”

Acclimatization to heat in man by controlled elevation of body temperature

“…Medical Research, London, N. W. 3 (Received 16 May 1962) The physiological changes which characterize acclimatization to heat have been frequently studied in the laboratory (Henschel, Taylor & Keys, 1943;Robinson, Turrell, Belding & Horvath, 1943;Horvath & Shelley, 1946;Eichna, Park, Nelson, Horvath & Palmes, 1950;Ladell, 1951;Bass, Kleeman, Quinn, Henschel & Hegnauer, 1955;Macpherson, 1960). The method used has been to mimic the natural situation with the subjects performing a carefully controlled work and rest routine for some hours each day in a controlled hot climate.…”