As the COVID-19 pandemic progresses, most companies and organizations are looking for ways to safely bring their employees back into the workplace. The obvious concern and challenge is ensuring that someone with COVID-19 – and who could potentially infect others inadvertently – is not allowed into the building.
One of the more interesting strategies to mitigate this risk is thermal imaging cameras that can detect workers who have fevers. Apple and Amazon are reportedly leveraging the technology, and the Centers for Disease Control (CDC) has suggested temperature checks to intercept potentially ill employees.
But can this work effectively for your workplace?
Understand thermal cameras’ limits before you invest
Thermal imaging cameras cannot determine if a person has COVID-19 or has been exposed to COVID-19 or any other virus or disease. What they can tell you, if used correctly, is if someone has an elevated body temperature, which is one of the symptoms of COVID-19.
However, as many as 25 percent of people with the virus are asymptomatic – and that includes not having a fever. Also, some of those who have a fever may be running a high temperature due to an illness or infection unrelated to COVID-19.
Familiarize yourself with thermal imaging and how it works
Thermal imaging or thermography detects heat or temperature with a lens, a sensor and a display that capture, analyze and showcases how much infrared radiation an object is emitting. All solid objects emit infrared radiation to some extent unless it is at absolute zero temperature. Generally, the higher the object’s temperature, the more infrared radiation it emits. After the level of heat or infrared radiation is captured and interpreted, it is translated into an electronic signal that creates an image on a display.
The temperature ranges are assigned a color palette where typically warmer temperatures are indicated progressively in yellow, orange and red hues, and cooler objects are depicted in greens, blues and purples.
Thermal imaging has been around for years and has various uses in the military and law enforcement communities and even at home. Each of these applications require different levels of resolution to fit their needs.
Several variables impact the sensitivity and effectiveness of thermal imaging cameras, the most important of which are pixel resolution and thermal sensitivity.
- As with a standard camera, higher pixel resolution results in an improved image and the ability to zoom into an area and maintain good image quality.
- The second area, thermal sensitivity, is a little more complicated. Each camera is rated at a thermal sensitivity range, which means at which increment of temperature the camera can differentiate (i.e., .5° F). Generally, higher pixel resolution and lower thermal sensitivity range cameras are better.
There are some limitations to thermal imaging cameras, as they:
- Lose effectiveness as the distance to the subject/object increases (loss of resolution)
- Cannot see through glass because it acts like a mirror and reflects infrared radiation
- Become more (and sometimes prohibitively) expensive based on the quality of the camera
Recognize there are some clear benefits …
Thermal imaging cameras can be an initial screening tool to determine if someone has an elevated body temperature. Using a thermal imaging system for this purpose is relatively quick, non-invasive and is as accurate as the system and setup allow.
… but you still need to review the intel yourself
However, to make this type of screening effective, it is highly important that you create reasonable expectations, use the right equipment and procedures, and have a plan for those whose temperatures register above the threshold you set.
To help create reasonable expectations, do your own research to understand how a thermal imaging camera might work for your specific situation and how you would implement its use in your environment. Also, review the CDC’s most updated information on COVID-19 symptoms and your state’s latest guidance on COVID-19 symptoms and detection. These sources will assist you in framing the expectations for your plan.
Another document you should reference is the Federal Drug Administration’s (FDA) Enforcement Policy for Telethermographic Systems During the Coronavirus Disease 2019 (COVID-19) Public Health Emergency. This document will provide you with some insight on how the FDA views thermal imaging systems and special considerations during the COVID-19 pandemic. This information may prove helpful when determining which equipment is best for you. Not every thermal imaging camera will be effective for this use. Be diligent in your research to ensure you select equipment that will work for you in your environment.
Form a team and create protocols
We suggest forming a team that includes representatives from Security, Legal, Human Resources, Risk Management and Facilities to help you look at the pros and cons of conducting screening in general and then specifically with a thermal imaging camera. Your team should develop policies and procedures that cover the use of thermal imaging for this purpose.
To that end, you need to consider what you are going to do if someone is detected with a temperature higher than your accepted threshold. Will you simply turn them away, or will you send them for additional screening and testing, and if so, where, and how will you handle that step? This is another reason why forming a team ahead of time to help develop a procedure that is effective and consistently applied.
If you install, don’t forget: location, location, location
Research indicates the most effective and accurate location on someone’s face to determine their core body temperature using a thermal imaging camera is the inner-eye canthus, an area over the tear duct. Any location besides that is going to give you a less accurate reading, which may lead to false negative results. This is in addition to other factors that may do so as well: sweating, stress, makeup, glasses and so on. Each camera or system manufacturer should provide specific setup and operation guidelines for their equipment to obtain optimal results.
Some will ask, “Why not use a touchless thermometer?” The main reason is you are measuring skin temperature and not core body temperature. Skin temperature levels can vary greatly, up or down, and can be impacted by clothing, weather, air conditioning and other factors. Someone who was sitting in the sun before having their temperature tested may reflect a false positive high temperature and someone sitting in an airconditioned car may test with a normal or low temperature that could also be a false negative.
Responsibly using a thermal imaging system to screen for high body temperature is not as simple as installing a camera and starting to screen people – but it could be an effective measure for identifying individuals with a fever, and could provide some peace of mind to a returning workforce.
If you’re looking into thermal imaging systems but not sure where to start, shoot us an email and one of our experts can walk you through the process.