Bilateral assessment of body core temperature through axillar, tympanic and inner canthi thermometers in a young population

There are several sites in which the human body core temperature can be estimated and used to identify febrile states in a threat of pandemic situations at high-populational-traffic places (e.g. airports, ports, universities, schools, public buildings). In these locations, a fast method is required for temperature screening of masses. The most common methods are axillar and tympanic thermometers. However, in addition, measurement of the inner canthi (IC) of the eye with infrared thermal (IRT) imaging has been suggested as a fast mass measurement screening tool. Objective: It is the aim of this research to identify the bilateral difference of the available body temperature screening methods with potential use for large-scale fever screening and to verify if such a difference is acceptable. Approach: A total of 206 young participants (104 females and 102 males) were recruited, having their temperatures taken with the different methods bilaterally under neutral environmental conditions. The obtained results were statistically processed. Main results: Results established absent reference data for site and method in west European populations. The bilateral differences were minor using the IC of the eye monitored with infrared imaging, which was also proved with the Bland-Altmann limits of agreement. Significance: Based on the findings of this research, despite all methods being able to estimate body core temperature, it is suggested to use IRT images of the IC of the eye, due to its fast, reliable and reproducible procedure for mass screening. Further research is required to understand the higher bilateral variability in using the traditional thermometer axilla and tympanic membrane assessments, since these are the methods currently used within a clinical setup. The same procedure must be applied to fever cases to establish a decision threshold per method.