Validity of Calera® Sensor for Assessing Core Temperature During Arm Crank Exercise in Individuals with Spinal Cord Injury in a Moderate Thermal Environment.

BACKGROUND: Wearables that allow core temperature to be monitored are an important development for athletes with spinal cord injury (SCI) due to their increased risk of suffering heat-related illness. OBJECTIVES: To assess the validity of the Calera® heat flux sensor compared to ingestible telemetric pills (BodyCap) for monitoring core temperature during a graded exercise test in individuals with SCI and non-SCI participants. METHODS: Twenty-one participants were included (SCI, 12; non-SCI, 9). The participants conducted a graded exercise test that consisted of 3-minute stages with 1-minute rest intervals, and core temperature was continuously measured using ingestible telemetric pills and the Calera® heat flux sensor. Intraclass correlation coefficients (ICC) and bias were calculated to assess agreement between methods, with comparisons made between SCI and non-SCI groups. RESULTS: In non-SCI participants, agreement between the methods was good [ICC = 0.65, P < .001; bias = 0.06 (0.22) °C; 95% CI 0.02 to 0.11 °C], while SCI participants showed poor agreement [ICC = -0.12, P = .93; bias = -0.11 (0.46) °C; 95% CI -0.19 to -0.03 °C]. The percentage of measurements where the mean difference between methods exceeded 0.3 °C was 15% in non-SCI participants and 42% in SCI participants. CONCLUSION: The Calera® heat flux sensor is not a valid tool for assessing core temperature in individuals with SCI in moderate thermal environments.