Performance of infrared ear and forehead thermometers: a comparative study in 205 febrile and afebrile children

Aims and objectives: This study compared readings from two professional-grade, commercially available infrared (IR) thermometers, the ThermoScan® PRO 4000 prewarmed tip ear thermometer and the Temporal Scanner(™) TAT-5000 temporal artery thermometer.

Background: The repeatability and precision of readings from IR thermometers for professional use were questioned in the past, but in recent years, these types of thermometers have been technologically improved, so their ability to replicate standard temperature readings reliably should be re-examined.

Design: Febrile and afebrile children were recruited from the emergency department, overflow treatment areas and the paediatric intensive care unit of a large hospital in Argentina. Each child had a randomised sequence of seven temperature readings, including three from the ear, three from the forehead or behind the ear and one reference oral or rectal reading.

Methods: Temperature readings were taken with the ThermoScan PRO 4000, the Temporal Scanner TAT-5000 and the monitor mode of SureTemp® Plus, a widely used professional-grade contact thermometer, for reference.

Results: Of 205 children, 46% were febrile, per reference thermometer readings. While mean ThermoScan PRO 4000 febrile measurements did not differ significantly from reference, mean Temporal Scanner TAT-5000 febrile measurements were significantly lower (by a mean of 0·42 °C) than the reference. Overall bias of the ThermoScan PRO 4000 was significantly lower than that of the Temporal Scanner TAT-5000; repeatability was 1·5 times higher, and overall false-negative rate was about a third that of Temporal Scanner TAT-5000, when compared to the reference.

Conclusions: This study indicates that the ThermoScan PRO 4000 provides measurements closer to those of a professional-grade contact thermometer when compared to the Temporal Scanner TAT-5000.

Relevance to clinical practice: The odds of misclassifying a febrile child as non-febrile were about threefold higher with the Temporal Scanner TAT-5000 temporal artery thermometer than with the ThermoScan® PRO 4000 ear thermometer.