Figure 1.
Representative tracing of the time course of core temperature (gastrointestinal temperature, Tgi), dry-bulb temperature (Tdb), and ambient water vapor pressure (Pa) for a MinAct trial with increasing Tdb. Lines are drawn through data points in the bottom panel to demonstrate the stepwise progression of Tdb. The Tgi inflection point represents the combination of environmental conditions above which heat stress becomes uncompensable and a stable core temperature can no longer be maintained. In this case, the Tgi inflection point (i.e., critical dry bulb temperature, Tcrit) occurs at Tdb = 46.1°C.