A Comparison between Conductive and Infrared Devices for Measuring Mean Skin Temperature at Rest, during Exercise in the Heat, and Recovery

Purpose Skin temperature assessment has historically been undertaken with conductive devices affixed to the skin. With the development of technology, infrared devices are increasingly utilised in the measurement of skin temperature. Therefore, our purpose was to evaluate the agreement between four skin temperature devices at rest, during exercise in the heat, and recovery. Methods Mean skin temperature ((T) over bar (sk)) was assessed in thirty healthy males during 30 min rest (24.0 +/- 1.2 degrees C, 56 +/- 8%), 30 min cycle in the heat (38.0 +/- 0.5 degrees C, 41 +/- 2%), and 45 min recovery (24.0 +/- 1.3 degrees C, 56 +/- 9%). (T) over bar (sk) was assessed at four sites using two conductive devices (thermistors, iButtons) and two infrared devices (infrared thermometer, infrared camera). Results Bland-Altman plots demonstrated mean bias +/- limits of agreement between the thermistors and iButtons as follows (rest, exercise, recovery): -0.01 +/- 0.04, 0.26 +/- 0.85, -0.37 +/- 0.98 degrees C; thermistors and infrared thermometer: 0.34 +/- 0.44, -0.44 +/- 1.23, -1.04 +/- 1.75 degrees C; thermistors and infrared camera (rest, recovery): 0.83 +/- 0.77, 1.88 +/- 1.87 degrees C. Pairwise comparisons of (T) over bar (sk) found significant differences (p < 0.05) between thermistors and both infrared devices during resting conditions, and significant differences between the thermistors and all other devices tested during exercise in the heat and recovery. Conclusions These results indicate poor agreement between conductive and infrared devices at rest, during exercise in the heat, and subsequent recovery. Infrared devices may not be suitablefor monitoring <(T)over bar>(sk) in the presence of, or following, metabolic and environmental induced heat stress.