Thermal imaging can be an effective mass-screening device for detecting individuals with an elevated body temperature in large groups.
As such, thermal imaging can provide useful information when used as a screening tool in high-traffic areas to help identify people with an elevated temperature compared to the general population.
Although thermal imaging cameras are primarily designed for industrial and night vision uses, public health organisations have used thermal imaging cameras around the world at airports, seaports, office buildings and other mass gathering areas to provide rapid, efficient thermal screening of high traffic areas.
Detecting elevated body temperatures
A thermal imaging camera produces thermal images or heat pictures that detect and display even the smallest temperature differences.
This allows thermal cameras to create a visual heat map of skin temperatures in real time. In addition, thermal imaging cameras are very sensitive devices, measuring temperature differences as small as 0.05ºC.
Thanks to the thermal imaging camera's built-in functions like colour and sound alarms that can be set to go off when a certain temperature threshold is exceeded, the operator can instantly decide whether or not the subject needs to be referred for further screening.
As the thermal imaging camera produces images in real time, the total evaluation process takes less than a second, making thermal imaging technology very useful for rapidly screening large numbers of people.
Measuring human body temperature
It's true that a person's general skin temperature is typically not equal to the person's core temperature. That doesn't detract from the use of thermal cameras to detect elevated body temperatures, however.
Thermal cameras are useful in this role because the goal is not to measure absolute body temperature, but to differentiate people who have an elevated body temperature compared to the crowd while taking into account the environmental conditions of the location.
The thermal imaging camera automatically detects the hottest temperature within an area, set by the operator. A colour alarm makes it easy to decide whether a person needs further screening or not.
The camera can be installed and used quickly and easily. It automatically calculates the average temperature of the first 10 people it scans and defines their average. The operator can then use this average as the basis for an alarm that will go off when the measured temperature reaches a specific temperature threshold above the average temperature (e.g., plus 1°C).
Sound and colour alarms
All areas on the subject's face that are hotter than a predefined temperature value can be displayed as a designated colour on the thermal image. This built-in alarm allows users to make an immediate decision regarding whether the subject requires further screening.
Cameras from FLIR are equipped with a sound alarm. If the temperature exceeds a predefined value, an audible alarm will go off, allowing the operator to select the person for further screening if needed.
A small investment to enable high traffic screening
Major airports in all over the world are already using thermal imaging cameras and have applied this methodology to screen all people entering and leaving the country. It is a quick, non-contact method that is safe for both the camera operator and the people being screened.
Cameras from thermal imaging specialist FLIR are particularly well suited to this because they can provide a temperature reading of a person's face in a matter of seconds.
FLIR thermal imaging cameras can be operated by non-specialists after a few hours of training.