Cold strain index applied to exercising men in cold-wet conditions

United States Army Research Institute of Environmental Medicine, Natick, Massachusetts 01760-5007 A cold strain index (CSI) based on rectal (T re ) and mean skin temperatures ( sk ) using data from seminude resting subjects has been proposed (Moran DS, Castellani JW, O'Brien C, Young AJ, and Pandolf KB. Am J Physiol Regulatory Integrative Comp Physiol 277: R556-R564, 1999). The current study determined whether CSI could provide meaningful data for clothed subjects exercising in the cold with compromised insulation. Ten men exercised in cold-wet conditions (CW) for 6 h before (D0) and after 3 days of exhaustive exercise (D3). Each hour of CW consisted of 10 min of standing in rain (5.4 cm/h, 5°C air) followed by 45 min of walking (1.34 m/s, 5.4 m/s wind, 5°C air). The change in T re across time was greater ( P