With many workplaces beginning to re-open or have gradual phased return to work the question is which technology, if any, do you use to assess infection in returning staff?
Many companies have opted to use temperature and moreover an abnormal rise in ‘core’ temperature to highlight possible cases of COVID-19.
If you are going to use temperature as a guide then you should be aware of the shortcomings so we’ve used peer reviewed evidence to give you the information you need.
So… what is normal ‘core’ temperature? The reality is, there isn’t one exact “normal” body temperature, so be prepared for a range of “normal”. However, the NHS consider a fever is usually when your body temperature is 37.8 C or higher.
Measurement of core temperature, if you want to be super accurate is best done using pulmonary artery catheterization as it is the reference standard to measure core body temperature, however we would not suggest you use this in the workplace…. “don’t do this at home folks”. Then of course there is the use of rectal and oral thermometers, which moderately correlates to core temperature but is also a tad invasive.
The tympanic (in your ear) infra-red thermometer frequently used in patient care has been shown to correlate with core body temperature and could be self administered to adhere to distancing guidance.
Handheld cutaneous (skin) infra-red thermometer is popularly used to screen large numbers of individuals due to it’s portability and that it does not require contact or cause discomfort to the individual being assessed, however there is little data to support its use.
Among common cutaneous infra-red thermometers evaluated for their ability to measure temperature traceable to the International Temperature Scale of 1990 (ITS-90), the majority performed outside the accuracy range stated by the manufacturers and the medical standard. (Fletcher et al 2018).
The handheld cutaneous infra-red thermometer was less accurate than the tympanic thermometer and other infra-red thermal systems for temperature measurements and fever detection. (Bijur et al, 2016, Lui et al, 2004, Hausfater et al, 2008 and Tay et al 2015).
The study by Tay et al 2015, showed that the handheld infra-red thermometer had a low sensitivity of 29.4% when compared with the oral thermometer to detect fever.
The performance of the hand held cutaneous infra-red thermometer is operator-dependent, as the thermometer is aimed at the temple or forehead, and distance between the thermometer and skin may affect its accuracy. It is not unlikely that sub-optimally trained operators, shying away from close contact with those being screened, hold the thermometer further away than the required proximity and thus compromise its effectiveness.
In a pandemic, a false negative is a false reassurance and a potential future infection cluster (Aw, 2020)
Information taken from The Journal of Hospital Infection.
AW, J. 2020. The non-contact handheld cutaneous infra-red thermometer for fever screening during the COVID-19 global emergency. The Journal of hospital infection, 104, 451-451.