Date of Graduation


Document Type


Degree Name

Bachelor of Science

Degree Level



Health, Human Performance and Recreation


McDermott, Brendon

Committee Member/Reader

Vandermark, Lesley

Committee Member/Second Reader

Ganio, Matthew


Validity and Reliability of Temperature Sensing Devices During and Following Exercise in the Heat

Covin, O., McDermott, B., Ganio, M., Vandermark, L.: Exercise Science Research Center, University of Arkansas, Fayetteville, AR

Background: Exertional heat stroke is a danger for athletes that participate in outdoor and indoor sports and can be fatal if not recognized and treated properly. Oral temperature is commonly used to assess an athlete’s temperature during exercise, but previous research suggests it may be an invalid and unreliable measurement of core temperature. A company recently designed a mouth guard prototype that changes color when core temperature reaches a specific threshold. Purpose: The purpose of this study was to determine the reliability and validity of the color-changing mouth guard when the user reaches a core temperature of 39°C. I hypothesized that the mouth guard would have limited validity and reliability. Methodology: Thirteen volunteers participated in the study (26 ± 5.28 yrs; 171 ± 8.14 cm; 70.1 ± 11.58 kg; 17.0 ± 4.75% body fat). Participants ingested thermistors 5-6 hours prior to their assigned trail time. When participants arrived, their height, nude body mass, and bioelectrical impendence were measured. They began their trial by sitting in the environmental chamber for 10 minutes. Then, a photo of the mouth guard was taken, and their oral (Welch Allyn SureTemp® Plus) and intestinal temperatures (CorTemp) were measured. Then they began exercise with the goal of reaching >39°C. Every 5 minutes, a photo of the mouth guard was taken, and temperature measurements were recorded. Exercise ceased when the participant wanted to stop, if they reached 40.2°C, or if they showed symptoms of heat exhaustion. After exercise, they sat in the chamber for 5 minutes, outside of the chamber for 5 minutes, and in a cold-water bath at 4.5-10°C for 5 minutes. A photo of the mouth guard and temperature measurements were taken after each of these events. After data collection, oral temperatures were compared to intestinal temperature in order to determine validity and reliability. Water baths were used to confirm that the mouth guards changed color at their reported temperature. Results: Each mouthguard changed color at the correct temperature. Participants exercised for a mean of 47 ± 13.67 minutes. The participants reached a mean intestinal temperature of 39.08 ± 0.18°C, which was significantly greater than maximal oral temperature (37.33 ± 0.39°C; p<.001). At no point during trials did the mouth guards change color, despite the fact that the mean core temperature was above the supposed threshold of the mouth guards. Discussion: The findings of this study support the idea that oral temperature is not a valid or reliable measurement of core body temperature during exercise. It would be unsafe for athletic trainers to use this mouth guard as a diagnostic or preventive tool for heat illnesses.

Funding Source: Dental Choice Holdings, Inc.


Exertional heat stroke, oral temperature, athletic trainers, core body temperature, mouth guard