“Skin temperature can be affected by ambient temperature. If it’s a very cold day your skin temperature will be cold,” she explained.
“For an actual diagnosis of having a fever it is your core temperature you need to take.”
She said infrared thermometers could provide false reassurance or lead to panic.
“It might say that you don’t have a fever when you actually do or you do have a fever and you actually don’t,” Professor Russell said. “It can give you the wrong information.”
She referred to international research which found while some devices failed to detect 96 per cent of fevers, others picked up 90 per cent of fevers.
The devices’ also falsely diagnosed patients with fevers, she said.
“You’d want a screening tool that performs better than that,” she said. “For the devices to be useful they need to not only detect fever but also have a low rate of false positives as these can lead to unnecessary tests, inconvenience and stress.”
While the devices have traditionally been used by parents wanting a non-intrusive way to check a baby’s temperature, they have become increasingly popular as a screening tool during the COVID-19 pandemic. They are usually positioned towards a person’s forehead, from a distance.
In July, the Victorian government distributed 14,000 of the devices to schools in greater Melbourne and Mitchell Shire, with students sent home and asked to get a COVID-19 test if they recorded a high temperature.
Concerns have also been raised about the reliability of fever as an indicator of COVID-19.
Data collected by Victoria’s public health team reveals that coughs, sore throats and runny noses are the most common symptoms being detected among those who test positive to coronavirus, with fever apparent in only about 20 per cent of infections.
Professor Caroline Miller, director of the health policy centre at the South Australian Health and Medical Research Centre, said there was limited value in using thermometers as a screening tool for coronavirus.
“A fever is not the most prevalent symptom for COVID,” she said. “Coughing is a more common symptom. And then people are infectious prior to them becoming symptomatic so they’re not reporting high temperatures. [Temperature screenings] don’t do a great job of predicting COVID at a population-level.”
She also raised concerns about the accuracy of non-contact infrared thermometers.
“They are a lot less precise compared to say a doctor taking your temperature in a clinic setting with a thermometer that goes into your ears.”
But Altona North GP Dr Mukesh Haikerwell said the devices had been a useful screening tool at his respiratory clinic, which has tested 1500 patients for coronavirus since April.
But he acknowledged the devices could be fiddly, and said they “conked out” if the weather was too hot or cold. “They have an optimum operating temperature,” he said.
Of the 44 complaints lodged with the TGA since the end of last March, four matters have been closed as no noncompliance was identified and eight are under current investigation.
“A number have been closed following correspondence with the advertiser,” a spokeswoman said.
Consumers have previously complained about inaccurate high readings on infrared thermometers, “abnormal and inconsistent values”, according to reports on the TGA’s website.
There are currently 320 electronic and infrared thermometers listed on the Australian Register of Therapeutic Goods, with the TGA receiving scores of new applications in response to COVID-19.
Senior Reporter at The Age