HUMAN RACIAL RESPONSES 

 T and T = temperatures of the warm and cool surfaces 



t = time 



d = thickness of the conductor 



It follows that tissue insulation may be determined from the 

 equation: 



K. = 



(^r - T^ 



i H 



where; 



o , / 2 / 

 K = tissue insulation C/kcal/m /hr 

 1 



T = average rectal temperature 



T = water temperature 

 w 



2 

 H = heat loss (kcal/m /hr) measured over 30 minutes 



For these calculations it is assumed that skin temperature is 

 equal to water temperature and that regional gradients over the 

 body have been obliterated. Although this assumption disregards 

 the temperature of the boundary layer between the skin- water inter- 

 face, the assumption has precedents (Carlson et al., 1958; Govino, 

 1960). 



Determination of Body Fat 



The skin fold calipers described by Best (1953) were used to 

 measure the thickness of ten double folds of skin and subcutaneous 

 fat at the sites recommended by Allen et al. (1956). Percentage of 

 adiposity was determined from the total skinfold thickness minus 40 

 mm (the thickness of ten double folds of skin) according to Allen's 

 formula. Percentage of adiposity was multiplied by 0.62 which 

 corrected for water in adipose tissue (Brozek et al., 19 54). 



361 



