Prediction of rectal temperature by the Questemp II personal heat strain monitor under low and moderate heat stress

This study assessed the use of aural canal temperature measured with the Qu estemp II personal heat strain monitor (Tq) relative to rectal temperature (Tre) during simulated industrial work in three different wet bulb globe te mperatures (WBGT). Sixteen subjects performed walking and arm curl exercise at a rate of 300 kcal/hour for 4 hours while wearing Saranex(R) protective coveralls in 18, 23, and 27 degrees C WBGT environments and wearing the Qu estemp II. Correlations were determined between Tre and Tq for the three co nditions and for all conditions combined. Pearson r values were 0.48 (18 de grees C WBGT), 0.42 (23 degrees C WBGT), 0.38 (27 degrees WBGT), and 0.50 ( all trials). Because a major concern is safe maximum core body temperature, means and standard deviations for differences between Tre and Tq were asse ssed at peak temperatures to determine the predictability of Tre from To so lely at these points. Large standard deviations in delta values relative to a small overall tolerable temperature range ruled out the use of To in thi s manner. Based on the current data, aural canal temperature as measured wi th the Questemp II did not provide an accurate reflection of Tre across tim e nor at peak core temperatures during low to moderate heat strain.