Is current body temperature measurement practice fit-for-purpose?

Abstract

There has been a marked rise in the number of avoidable deaths in health services around the world. At the same time there has been a growing increase in antibiotic resistant so-called "superbugs." We examine here the potential role of body temperature measurement in these adverse trends. Electronic based thermometers have replaced traditional mercury (and other liquid-in-glass type) thermometers for reasons of safety rather than superiority. Electronic thermometers are in general less robust from a measurement perspective than their predecessors. We illustrate the implications of unreliable temperature measurement on the diagnosis and management of disease, including COVID-19, through statistical calculations. Since a return to mercury thermometers is both undesirable and impractical, we call for better governance in the current practice of clinical thermometry to ensure the traceability and long-term accuracy of electronic thermometers and discuss how this could be achieved.

The importance of body core temperature evaluation in balneotherapy

“…Non-invasive measurements are performed mostly in the mouth (oral), axilla, tympanic (ear canal), and forehead (skin and temporal artery). Electronic contact thermometers and infrared thermometers are used as measuring devices (Moran and Mendal 2002;Machin et al 2021). Practical use of mercury thermometers, used as noninvasive temperature measurement devices, has reduced in recent years as a result of prohibitions on use in many countries due to injury from broken glass and toxic effects of mercury (European Parliament Directive 2007/51/EC; Machin et al 2021).…”

“…In direct mode, measurement duration is long due to the time needed for thermal equilibration between the thermometer and measurement region (Ring et al 2010). Additionally, temperature measurement durations are clearly shortened when used in predictive mode (Machin et al 2021). However, the accuracy of thermometers in this mode is lower compared to direct mode (Crawford et al 2006).…”

“…Axillary temperature measurement has disadvantages since it is affected by sweat and ambient temperature (Crawford et al 2006;Marui et al 2017;Sims et al 2018), and frequent displacement of the thermometer during measurement due to the structure of the armpit (Machin et al 2021).…”

“…Tympanic IR thermometers work on the basis of identifying infrared radiation emitted by the tympanic membrane (Crawford et al 2006). It is accepted as a suitable region for BCT measurement due to being close to the hypothalamus and perfused by the internal carotid artery (Yeoh et al 2017;Machin et al 2021). Skin IR thermometers include non-contact infrared forehead thermometers and temporal artery thermometer (TAT) types (Bolton et al 2020).…”

“…The accuracy of IR thermometer measurements may be affected by causes of uncertainty like ambient temperature, emissivity (the ability of an object to emit or absorb thermal radiation) (Shaw and Marston 2000), and mean radiant temperature (Zehner and Terndrup 1991;Dell'Isola et al 2021). For tympanic thermometers, the presence of cerumen (ear wax) in the ear canal (Daanen 2006); for IR skin thermometers, wrong measurement distance, wrong angle and dirty lens, sweat, makeup, and lotion (Crawford et al 2006;Barry et al 2016;Sullivan et al 2021); and for TAT, the inability to fully identify the artery location and inclusion of larger regions adjacent to the thermometer in the measurement (Machin et al 2021) are situations that negatively affect temperature measurement.…”