Measuring skin temperature before, during and after exercise: a comparison of thermocouples and infrared thermography

Measuring skin temperature (T-SK) provides important information about the complex thermal control system and could be interesting when carrying out studies about thermoregulation. The most common method to record T-SK involves thermocouples at specific locations; however, the use of infrared thermal imaging (IRT) has increased. The two methods use different physical processes to measure T-SK, and each has advantages and disadvantages. Therefore, the objective of this study was to compare the mean skin temperature (MTSK) measurements using thermocouples and IRT in three different situations: pre-exercise, exercise and post-exercise. Analysis of the residual scores in Bland-Altman plots showed poor agreement between the MTSK obtained using thermocouples and those using IRT. The averaged error was -0.75 degrees C during pre-exercise, 1.22 degrees C during exercise and -1.16 degrees C during post-exercise, and the reliability between the methods was low in the pre-(ICC = 0.75 [0.12 to 0.93]), during (ICC = 0.49 [-0.80 to 0.85]) and post-exercise (ICC = 0.35 [-1.22 to 0.81] conditions. Thus, there is poor correlation between the values of MTSK measured by thermocouples and IRT pre-exercise, exercise and post-exercise, and low reliability between the two forms of measurement.