What do thermal imaging cameras do?
Using infrared technology, thermal cameras detect radiating heat from a body, usually from the forehead and then estimate core body temperature. But they are not designed to be medical devices.
They can give a reasonable measure of skin temperature, to within half a degree, but that is not the same as body temperature. They are less accurate than medical device thermometers like those you stick in the ear according to medical experts.
What is normal body temperature?
About 37C (98.6F). A high temperature is usually considered to be 38C or over. But normal temperature can vary from person to person and change during the day. It can also fluctuate during a woman's monthly cycle.
Do thermal cameras detect coronavirus?
No, they only measure temperature. A high temperature or fever is just one common symptom of the virus. Others include nausea, headaches, fatigue and loss of taste or smell. Not everyone with the virus gets a high temperature and not everyone with a high temperature is infected with coronavirus.
So thermal cameras alone will miss infected people with other symptoms or no symptoms at all, known as false negatives. They will also identify people unwell with a fever for another reason, known as false positives.
So, are thermal cameras useful?
On its own, temperature screening "may not be very effective" says the World Health Organization. Cameras must be set up correctly and take account of ambient temperature. A risk is that cameras can lull operators into a false sense of security.
What if I am wearing a face mask or covering?
Heat radiating from the skin will likely be impacted by wearing face masks, however most temperature measurements are based on the forehead which is usually exposed.
Will I be hotter if after exercising?
Skin temperature goes down during exercise as sweat appears on the surface of the skin.
A Positive in Thermal Camera Use ?
Employees could perceive this as an additional control and feel safer in their workplace
Additional General Thoughts?
- Presumably, the screening would have to be manned by trained personnel and perhaps a private area allocated for communication in the event of negative results
- Fever or body temperature alone can be a poor indicator of viral infection and therefore complicates the validity of thermal scanning for COVID-19 surveillance.
- Fevers can be masked by anti-inflammatory drugs
- Non-infectious conditions, such as pregnancy, menopause, or inflammation, however, might also cause elevated temperature, which can render thermal scanning as highly sensitive but non-specific to any condition.
- Inconsistencies or variations in viral response or strain can render thermal scanning insufficient for detecting specific types of respiratory viruses.
- Potential GDPR breach, as it is assumed if a person were refused access the person details would have to recorded
And finally Travel e.g. Airports?
World Health Organisation have stated for International Travel?
“Temperature screening alone, at exit or entry, is not an effective way to stop international spread, since infected individuals may be in incubation period, may not express apparent symptoms early on in the course of the disease, or may dissimulate fever through the use of antipyretics; in addition, such measures require substantial investments for what may bear little benefits.
It is more effective to provide prevention recommendation messages to travellers and to collect health declarations at arrival, with travellers' contact details, to allow for a proper risk assessment and a possible contact tracing of incoming travellers”