By: Christopher Sirota, CPCU
Key Takeaway: Thermal scanners, often used at building entrances, that are not approved by the FDA or used improperly may be providing false indications.
Midway through the pandemic in 2020, the Food and Drug Administration (FDA) reportedly decided to temporarily lift a vetting requirement for thermal scanners. A new study indicates some unvetted machines may have a flaw that impacts their performance.
According to a study conducted by a surveillance technology group, a comparison of vetted thermal scanners with unvetted ones revealed that there may be a software algorithm in many unvetted devices that compensates for the low sensitivity of some low-cost sensors by adjusting the calculated body temperature; in other words, certain scans may adjust observed temperatures higher or lower towards normal, healthy body temperature. Per the study, skewed temperature results could lead to a false sense of security in locations such as schools, airports and hotels, potentially allowing someone with an illness to enter the location.
Even with an FDA-vetted device, the study highlights that proper procedures and conditions are needed for accurate body temperature readings.
In fact, in March 2021, the FDA released an alert to consumers and healthcare providers about proper use of thermal scanners; the FDA also announced it had sent warning letters to several companies for illegal sales of such devices.
The FDA announcement explains the concerns about proper use as follows:
Improper use of thermal imaging systems may lead to inaccurate body temperature measurements which can present potentially serious public health risks. Such risks may include, but are not limited to, the device incorrectly detecting a normal human body temperature when a person has an elevated temperature and incorrectly assessing a person to have an elevated body temperature when they do not. These risks are more likely to be present where thermal imaging systems scan multiple individuals simultaneously
The FDA's recommendations includes the following:
- These devices measure skin surface temperature, so the person's skin needs time to adjust to environmental changes, for example when entering a building. Some of these environmental factors are air temperature, humidity, wind, and sunlight.
- The area where you will use a thermal imaging system should be between 68-76 °F (20-24 °C). Temperatures outside this range can change skin temperature, so it may not reflect the person's internal body temperature. Additionally, the room should not have a draft (air movement) because it can change skin temperature. […]
- Thermal imaging systems should not be used near strong light sources, such as sunlight or bright electric lighting. Also, the system should not be facing anything that can reflect light such as windows or shiny surfaces.