Measurement of mean skin temperature of clothed persons in cool environments.

The precision with which mean skin temperature could be estimated from some few points on clothed persons in a cool environment was studied. The skin temperature data were obtained from experiments on 10 clothed persons who were resting and working at an environmental temperature of 10 degrees C. With these data, eleven calculation formulas in current use were compared to a "reference mean skin temperature" based on a weighting formula involving 13 local skin temperatures. It was concluded that no formula including less than seven points gave a reasonably accurate mean skin temperature in this cool environment. In addition, a stepwise correlation analysis involving linear regression was performed on the data. This gave 12 new calculation formulas, which were evaluated for accuracy in estimating mean skin temperature. Among these, a weighting formula involving only four local skin temperatures was selected to be recommended for use in field investigations: Tsk = 9.429 + 0.137 X Tforehead + 0.102 X Thand + 0.290 X Tlower back + 0.173 X Tlower leg.