Questions about Using Thermal Imaging Systems during COVID-19

Q: Are thermal imaging systems effective for screening people for fevers in places like nursing homes, airports, and hospital emergency rooms?

photo FDA

A: When using a thermal imaging system, it is important to assess whether the system will provide the intended results in high throughput areas. We understand that these devices are being used for initial temperature assessment and triage of individuals for elevated temperatures in medical and non-medical environments. They should not be used for measuring temperatures of many people at the same time in crowded areas, in other words “mass fever screening” is not recommended.

Based on where the system will be used, there may be more appropriate methods to initially assess and triage people, especially if there is a risk that infected people would not be identified right away. For example:

In a nursing home, inaccurate temperature measurement or a missed contagious person without a fever could spread infection among nursing home residents. So, in this case, other assessment options and following infection control practices may be more effective.

In airports, workplaces, grocery stores, concert venues, or other areas where you are trying to screen large groups of people for mass fever screening, diagnostic testing may be too difficult because of the time and costs needed to screen and get results. These systems will likely miss most individuals with COVID-19 who are contagious. Thermal imaging systems could be considered as one method for initial temperature assessment in these types of settings when used as part of a larger approach to risk management.

In a hospital emergency room, a thermal imaging system may help to quickly assess temperature and triage patients to determine who needs more evaluation or isolation.

Q: Are thermal imaging systems effective as the sole means of diagnosing COVID-19?

A: No. A fever or higher body temperature is only one possible symptom of a COVID-19 infection. Thermal imaging systems generally detect a high body temperature accurately when used appropriately. They do not detect any other infection symptoms, and many people with COVID-19 can be contagious without a fever. Also, a high body temperature does not necessarily mean a person has a COVID-19 infection.

All fevers measured by thermal imaging systems should be confirmed by another method and followed by more diagnostic evaluations for other symptoms, as appropriate.

Q: How can thermal imaging systems help with the COVID-19 response?

A: To help address urgent public health concerns raised by shortages of temperature measurement products and expand the availability of telethermographic systems used for initial body temperature for triage use during this COVID-19 public health emergency, the FDA is applying regulatory flexibility for certain telethermographic systems as outlined in its enforcement policy.

When a high body temperature is identified by thermal imaging, an additional evaluation should follow (for example, doctor evaluations or interview, laboratory testing and patient observation).

Q: Are thermal imaging systems used for body temperature assessment considered medical devices?

A: As discussed in the enforcement policy, telethermographic systems are devices when they are intended for a medical purpose. To determine if these products are intended for a medical purpose, FDA will consider whether:

They are labeled or otherwise intended for use by a health care professional;

They are labeled or otherwise for use in a health care facility or environment; and

They are labeled for an intended use that meets the definition of a device, for example, body temperature measurement for diagnostic purposes, including in non-medical environments.

Q: How does a thermal imaging system differ from a thermometer?

A: Both thermal imaging systems and non-contact infrared thermometers (NCIT) can measure surface temperatures without contact. An NCIT measures surface temperature in a single location, whereas a thermal imaging system can measure temperature differences across multiple locations, creating a relative temperature map of a region of the body. The enforcement policy in the guidance applies to use of thermal imaging systems to determine initial body temperature measurements.

There is a separate enforcement policy that applies to certain NCITs and other clinical electronic thermometers: Enforcement Policy for Clinical Electronic Thermometers During the Coronavirus Disease 2019 (COVID-19) Public Health Emergency.

Note, this information is applicable to thermal imaging systems that are intended for a medical purpose. This means that the system is intended for use in the diagnosis of disease or other conditions, or in the cure, mitigation, treatment or prevention of disease and, therefore, meets the definition of “device” set forth in Section 201(h) of the Federal Food, Drug, and Cosmetic Act.

For more information on FDA’s policies for these devices, and recommendations on their design, labeling, and use during the COVID-19 Public Health Emergency, please review the following:

Enforcement Policy for Telethermographic Systems During the Coronavirus Disease 2019 (COVID-19) Public Health Emergency: Guidance for Industry and Food and Drug Administration Staff

Additional information on these devices can be found at:

IEC 80601-2-59: Medical electrical equipment – Part 2-59: Particular requirements for basic safety and essential performance of screening thermoghraphs for human febrile temperature screening. 2017, International Electrotechnical Commission & International Organization for Standardization.

ISO/TR 13154: Medical electrical equipment — Deployment, implementation and operational guidelines for identifying febrile humans using a screening thermograph. 2017, International Organization for Standardization.

Ghassemi, P., et al. (2018). “Best practices for standardized performance testing of infrared thermographs intended for fever screening.” PLoS ONE 13(9): e0203302External Link Disclaimer.