key: cord-0724707-cl0pln2j
authors: Carpenè, Giovanni; Henry, Brandon Michael; Mattiuzzi, Camilla; Lippi, Giuseppe
title: Comparison of forehand temperature screening with infrared thermometer and thermal imagine scanner
date: 2021-02-13
journal: J Hosp Infect
DOI: 10.1016/j.jhin.2021.02.009
sha: 91579139ac95f7a154cc8a5253621ce438c76a8e
doc_id: 724707
cord_uid: cl0pln2j

nan

The assessment of body temperature with thermal imagine scanners and/or noncontact infrared thermometers to screen individuals for potential severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is now widespread in most healthcare facilities, as well as in a vast array of other social environments.

Nonetheless, the reliability of this strategy is plagued by some biological (i.e., high rate of asymptomatic SARS-CoV-2 infections, prevalence of fever of ~80% in coronavirus disease 2019, anti-pyretic use) and practical (i.e., impact of environmental temperature, device accuracy) drawbacks [1] [2] [3] . In order to mitigate the frequent imprecision of infrared forehead temperature devices, Hsiao et al. recently suggested that body temperature measurement should be repeated at least twice after subjects have acclimatized to the indoor environment [4] . To provide further evidence on this matter, this observational study aimed to compare forehand temperature values concomitantly measured with an infrared thermometer and a thermal imagine scanner, both routinely used for personnel and outpatients screening before hospital access.

The study population consisted of 24 consecutive healthcare workers (16 women and 8 men; mean age: 42±14 years, range 19-65 years), who underwent routine forehand temperature scanning before entering the hospital building at the University Hospital of Verona (Verona, Italy). As repeated body temperature screening with infrared thermometer and/or thermal imagine scanner is mandatory before hospital entry and while moving within different wards or laboratories, Ethics Committee approval and informed consent were unnecessary. The forehand temperature measurement was first repeated 10 times on the same subject with the same thermal imagine scanner Two important findings have emerged from our study. First, despite that the cumulative imprecision of both devices was <1%, and hence almost acceptable, the precision of the thermal imagine scanner used in our investigation was 3-fold better than that of the infrared thermometer (i.e., 0.2% vs. 0.6%), such that the use of the former device would appear more reliable for widespread body temperature screening, especially for testing people before accessing healthcare facilities, as in our case. When thermal imagine scanners are unavailable, we thus endorse the suggestion of Hsiao et al. [4] , that repeated measurements of forehand temperature with infrared thermometers may be necessary for obtaining a more precise measure. The second important aspect, is that forehand temperature measured with the two devices did not appear to be well aligned, as attested by the poor correlation found between values, and by observation of a clear temperature-dependent bias (Figure 1 ). This would imply that these two forehand temperature detectors could not be used interchangeably for systematic monitoring the body temperature of the healthcare staff across an institution. 

The Proportion of SARS-CoV-2 Infections That Are Asymptomatic: A Systematic Review

A brief report on the normal range of forehead temperature as determined by noncontact, handheld, infrared thermometer

Accuracy of peripheral thermometers for estimating temperature: a systematic review and meta-analysis

Measurement of body temperature to prevent pandemic COVID-19 in hospitals in Taiwan: repeated measurement is necessary

The authors wish to thank all the healthcare workers who contributed to this study.

None declared.

This work received no funding.J o u r n a l P r e -p r o o f