As discussed further below, scientific studies support that certain tele thermographic systems, also known as thermal imaging systems, may be used to measure surface skin temperature. These systems include an infrared thermal camera and may have a temperature reference source. In this document, they are referred to as thermal imaging systems.
Body temperature scanning system and non-contact infrared thermometers (NCITs) use different forms of infrared technology to measure temperature. For information about NCITs, please refer to the fact sheet on Non-contact Infrared Thermometers.
Thermal Imaging Systems and COVID-19
- When used correctly, thermal imaging systems generally have been shown to accurately measure someone’s surface skin temperature without being physically close to the person being evaluated. Thermal imaging systems offer certain benefits in that other methods need a closer proximity or contact to measure temperature (for example, non-contact infrared thermometers or oral thermometers).
- Temperature-based screening, such as thermal imaging, is not effective at determining if someone definitively has COVID-19 because, among other things, a person with COVID-19 may not have a fever. A diagnostic test must be performed to determine if someone has COVID-19.
- Thermal imaging systems have not been shown to be accurate when used to take the temperature of multiple people at the same time. The accuracy of these systems depends on careful set-up and operation, as well as proper preparation of the person being evaluated.
- Thermal imaging systems have been used by several countries during epidemics, although information about their effectiveness as part of efforts to reduce the spread of disease has been mixed.
- The FDA issued the Enforcement Policy for Telethermographic Systems During the Coronavirus Disease 2019 (COVID-19) Public Health Emergency guidance to help expand the availability of thermal imaging systems and mitigate thermometer shortages during the public health emergency. The guidance sets forth an enforcement policy that is intended to apply to all thermal imaging systems that are intended for medical purposes for the duration of the public health emergency related to COVID-19, and provides recommendations regarding performance and labeling of such systems.
Benefits of Thermal Imaging Systems
- The person who handles the thermal imaging system is not required to be physically close to the person being evaluated. In fact, the person who handles the thermal imaging system could be in a different area or room.
- The thermal imaging system may measure surface skin temperature faster than the typical forehead or oral (mouth) thermometer that requires a close distance or physical contact with the person being evaluated.
- Scientific studies show that, when used correctly, thermal imaging systems generally measure surface skin temperature accurately.
Limitations of Thermal Imaging Systems
- Although these systems may be in use for initial temperature assessment to triage individuals in high throughput areas (for example, airports, businesses and sporting events), the systems have not been shown to be effective when used to take the temperature of multiple people at the same time. They should not be used for “mass temperature screening.”
- These systems measure surface skin temperature, which is usually lower than a temperature measured orally. Thermal imaging systems must be adjusted properly to correct for this difference in measurements.
- These systems work effectively only when all the following are true:
- The systems are used in the right environment or location.
- The systems are set up and operated correctly.
- The person being assessed is prepared according to instructions.
- The person handling the thermal imaging system is properly trained.
Proper Use of Thermal Imaging Systems
The person who handles the system should follow all manufacturer instructions to make sure the system is set up properly and located where it can measure surface skin temperature accurately.
The person who handles the system should be trained to properly prepare both the location where the system will be used, and the person being evaluated, to increase accuracy. For details, see the standards and scientific papers listed under References below.
