Field measurement of core temperature typically requires rectal or other invasive, expensive core temperature methods. Infrared (IR) thermography uses a handheld camera to measure surface temperature at discrete locations. We attempted to validate IR thermography against core-temperature capsules for the tracking of core-temperature changes at rest, during exercise, and recovery.

Infrared thermography is a noninvasive method to follow changes in core temperature during exercise.

Twelve athletes swallowed an ingestible core-temperature (CorTemp) capsule 1-hour prior to exercise. Athletes refrained from drinking for 2 hours prior to or during the study. Temperatures were obtained using both the CorTemp capsule and IR thermography at 10-minute intervals for 30 minutes before exercise, during 30 minutes of moderate intensity aerobic exercise, and for 30 minutes of recovery. The temperatures were then averaged for each segment of data collection.

Prospective descriptive study.

Infrared thermography results (rest = 34.7°C C 0.49, exercise = 34.1°C ± 0.77, recovery = 34.6°C ± 0.46) were significantly lower than with the CorTemp capsules (rest = 37°C ± 0.55, exercise = 38.6°C ± 0.47, recovery = 37.7°C ± 0.47) throughout the data collection period. There were no significant correlations between the two measurement methods (rest = 0.22, exercise = 0.07, recovery = 0.59; all p > 0.05).

Infrared thermography is not a valid method to track core-temperature changes during exercise. In addition to IR thermography readings being consistently lower, temperature changes before, during, and after exercise showed wide and inconsistent variability.

Boggess BR, Stafford H, Moorman CT III, Berkoff DJ. Infrared Thermography: Not a Valid Method to Track Changes in Core Temperature in Exercising Athletes. The Duke Orthop J 2017;7(1):46-50.