Thermal resistance parameters of the air environment at various altitudes.
The thermal properties of atmospheric air surrounding the human body at various altitudes are characterized with a system of parameters. This system comprises resistance of the air to convective heat transfer h(c)(-1), degrees C (W/m2)(-1) and to water vapour transfer h(D)(-1), s/m. The concept of 'evaporative resistance' h(e)(-1), hPa (W/m2)(-1) following the similarity of the processes is introduced. In obtaining the altitude dependencies of investigated parameters, a respective heat transfer equation expressing the rate of heat exchange at the boundary body surface-ambient air is applied. The use of the body thermal state of the established attitude dependencies is discussed. The concept of 'thermal stability' related to the evaporative resistance parameter h(e)(-1)is introduced. This parameter is assumed as: (1) an indicator of the human body thermal stability and (2) distributor and predictor of environmental influence on the body thermal state.
Kandjov
I M
IM
Medical Climatology Department, National Centre of Physical Therapy, Sofia, Bulgaria.
D000388:Air; D000531:Altitude; D001833:Body Temperature Regulation / Q000502:physiology*; D004777:Environment; D006801:Humans; D008433:Mathematics; D008954:Models, Biological; D013816:Thermodynamics