Temporal Scanning Inaccurate for Body Temperature
Method detects forehead skin temperature through infrared scanning
THURSDAY, July 12 (HealthDay News) -- Temporal scanning thermometry, which tracks internal body temperature by detecting the highest forehead skin temperature by infrared scanning, does not accurately detect increases in internal body temperature after heat stress, researchers report in the July issue of Medicine & Science in Sports & Exercise.
Craig G. Crandall, Ph.D., and colleagues from Presbyterian Hospital of Dallas in Texas compared temporal scanning thermometry and an ingestible-pill telemetry system that tracks intestinal temperature in 16 subjects who underwent whole-body passive heat stress using a water-perfused suit. Subjects were heated to normal temperature (34 degrees Celsius) or heat stressed (48 degrees Celsius).
The researchers found that heat stress significantly increased heart rate, mean skin temperature, skin blood flow and sweat rate. However, after 30 minutes of heating, the temporal scanning temperature fell below the baseline pre-heat stress temperature, while the intestinal temperature increased significantly by a mean of 0.39 degrees Celsius. Further increases in intestinal body temperature and further decreases in temporal scanning temperature were observed for the 11 subjects who were heat stressed for 50 minutes.
"These results demonstrate that temporal scanning does not track internal temperature, as measured via intestinal temperature, during passive heating," Crandall and colleagues conclude. "Given these findings, it is recommended that this technique not be used to assess temperature in hyperthermic diaphoretic subjects."