This evaluation has several methodologic strengths. The major strength is the use of continuous Tc measurements rather than skin temperature. In addition, pre- and postshift blood and urine measurements assessed volume depletion. Limitations of this evaluation include the inability to compare differences in physiologic markers for heat stress and strain in potroom employees working 8-hour shifts and those working an additional overtime shift because of the small number of employees who worked overtime during our evaluation. In addition, the outdoor temperatures on the days of monitoring were cooler than expected during the summertime in Texas, and the heat strain and symptom data may have underestimated what potroom employees might experience during extreme heat.