reliable industrial measurement of body temperature. The use of infrared thermometry of tympanic temperature to determine body temperature in industrial conditions.

This study explored the potential use of infrared (IR) thermometry, measuring the temperature within the ear canal, as a relatively non-invasive indicator of the risk of heat stress in industrial applications. Measurements of body temperature using this technique, benchmarked against the intragastric (IG) temperature pill, were obtained from workplaces in the glass manufacturing and refractories sectors. Analysis of the more than 250 data pairs obtained showed that the variability in the IR temperature readings was too great for such measurements to be used to predict actual core temperature (as indicated by IG temperature). Further analysis initially suggested that it could be used as a monitoring or screening tool to ensure that core temperature was not exceeding a critical level. However, when the outcome was adjusted to reflect the inter-subject variability, the variance in the data set was too large to permit the core temperature to be predicted with sufficient confidence to allow it to be used, even as an initial measure to flag a need for more accurate measurement. There are indications from the literature that the make of measuring instrument used and the technique adopted in their use are important sources of variation. It remains to be seen whether refinements to the technique used, either in the manner of use or the circumstances of use, reduce this variance to a more satisfactory level.