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Solar heat load: heat balance during exercise in clothed subjects

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Summary

Six subjects exercised for 60 min on a cycle ergometer. Their backs were exposed to an artificial ‘sun’ with a spectral distribution similar to sunlight and an intensity of 724 W m−2. Each subject took part in four experiments in random order: wearing suits of polyester (insulation value = 0.5 clo), white (WP) or black (BP), or cotton (0.6 clo), white (WC) or black (BC). Measured by partitional calorimetry, the calculated heat losses and gains for the four conditions balanced within less than 10%. The differences between the short-wave radiation gains of subjects in white or black garments were small. This is due to the transparency of the white materials, which allows a larger percentage of the radiation to penetrate the clothing. The surface temperatures of the sun-exposed areas were very high, especially in the black suits. This promotes dry heat loss. Therefore the sweat loss in the black suits and the differences between the black and white clothes became relatively small. The physiological strain in steady-state exercise, as expressed by average heart rates, was 142 (WP), 154 (BP), 151 (WC), and 160 (BC) beats min−1; the sweat losses were 649 (WP), 666 (BP), 704 (WC), and 808 (BC) g. For both of these measures values for white polyester were significantly less than those for black cotton.

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References

  • Adolph EF (1938) Heat exchanges of man in the desert. Am J Physiol 123:486–499

    Google Scholar 

  • Adolph EF, Brown AG, Goddard DR, Gosselin RE, Kelly JJ, Molnar GW, Rahn H, Rothstein A, Towbin EJ, Wills JH, Wolf AW (1947) Physiology of man in the desert. Interscience, New York

    Google Scholar 

  • Beckenridge JR, Goldman RF (1971) Solar heat load in man. J Appl Physiol 31:659–663

    Google Scholar 

  • Berglund LG, Fashena D, Su X, Gwosdow A (1987) Evaporative weight loss as a measure of absorbed thermal radiation in the human. Proceedings of the 13th Annual North East Bioengineering Conference. Foster KR (ed) Institute of electrical and electronic engineers, Inc., New York, pp 507–510

    Google Scholar 

  • Blum HF (1945) The solar heat load: its relationship to total heat load and its relative importance in the design of clothing. J Clin Invest 24:712–721

    Google Scholar 

  • Borut AR, Dmi'el R, Shkolnik A (1979) Heat balance of resting and walking goats: comparison of climatic chamber and exposure in the desert. Physiol Zool 52:105–112

    Google Scholar 

  • Burton AC, Edholm OG (1955) Man in a cold environment. Arnold, London

    Google Scholar 

  • Clark, JA, Cena K (1978) Net radiation and beat transfer through clothing: the effects of insulation and colour. Ergonomics 21:691–696

    Google Scholar 

  • Clark, JA, Cena K, Monteith JL (1973) Measurements of the local heat balance of animal coats and human clothing. J Appl Physiol 35:751–754

    Google Scholar 

  • Ellis HI (1980) Metabolism and solar radiation in dark and white herons in hot climate. Physiol Zool 53:358–372

    Google Scholar 

  • Fanger PO (1970) Thermal comfort. Danish Technical Press, Copenhagen

    Google Scholar 

  • Finch VA, Dmi'el R, Boxman R, Shkolnik A, Taylor CR (1980) Why black goats in hot deserts? Effect of coat color on heat. exchanges of wild and domestic goast. Physiol Zool 53:19–25

    Google Scholar 

  • Gagge AP, Hardy JD (1967) Thermal radiation exchange of the human body by partitional calorimetry. J Appl Physiol 23:248–258

    Google Scholar 

  • Hardy JD, DuBois EF (1938) The technique of measuring radiation and convection. J Nutr 15:461–475

    Google Scholar 

  • Holmér I, Elnäs S (1981) Physiological evaluation of the resistance to evaporative heat transfer by clothing. Ergonomics 24:63–74

    Google Scholar 

  • Jacques JA, Huss J, McKeehan W, Dimitrof JM, Kuppenheim HF (1955) Spectral reflectance of human skin in the region 0.7 μ-2.6 g. J Appl Physiol 8:297–299

    Google Scholar 

  • Kerslake DMck (1972) The stress of hot environments. Cambridge University Press, Cambridge

    Google Scholar 

  • Krogh A, Trolle C (1936) A balance for the determination of insensible perspiration in man and its use. Scand Arch Physiol 73:159–162

    Google Scholar 

  • Nielsen B, Kassow K, Aschengreen FE (1988) Heat balance during exercise in the sun. Eur J Appl Physiol 58:189–196

    Google Scholar 

  • Olesen BW, Madsen TL (1983) Measurements of thermal insulation of clothings by a movable manikin. Proceedings of the International Conference on Medical and Biophysical Aspects of Protective Clothing. Henane R (ed) Institute des Santes Armees, Lyon, pp 205–213

    Google Scholar 

  • Roller WL, Goldman RF (1968) Prediction of heat load on man. J Appl Physiol 24:717–721

    Google Scholar 

  • Stolwijk JAJ, Hardy JD (1966) Partitional calorimetric studies of responses of man to thermal transients. J Appl Physiol 21:967–977

    Google Scholar 

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Nielsen, B. Solar heat load: heat balance during exercise in clothed subjects. Europ. J. Appl. Physiol. 60, 452–456 (1990). https://doi.org/10.1007/BF00705036

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