Eur J Appl Physiol (1992) 65:492-498 European Journal of
Applied
Physiology and Occupational Physiology © Springer-Verlag1992
Thermoregulatory responses of young and older men to cold exposure Yoshimitsu Inoue 1, Mikio Nakao 2, Tsutomu Araki 3, and Hiroyuki Ueda 4 1 Department of Hygiene, Kobe University School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650, Japan 2 Osaka University of Economics, Osaka 533, Japan 3 Hyogo University of Teacher Education, Kato-gun 673-14, Japan 4 Osaka Shin-ai College, Osaka 536, Japan Accepted July 13, 1992
Summary. Nine young (20-25 years) and ten older (6071 years) men, matched for body fatness and surface area:mass ratio, underwent cold tests in summer and winter. The cold tests consisted of a 60-min exposure, wearing only swimming trunks, to an air temperature of 17° C (both seasons) and 12° C (winter only). Rectal (Tre) and mean skin (~k) temperatures, metabolic heat production (M), systolic (BP~) and diastolic (BPd) blood pressures and heart rate (fc) were measured. During the equilibrium period (28°C air tem_perature) there were no age-related differences in Tre, Tsk, BPs, BPd, or fc regardless of season, although M of the older men was significantly lower ( P < 0.003). The decrease in Tre and Tsk (due to the marked decrease in six of the older men) and the increase in BPs and BPd were significantly greater (P