Elevated Temperature Screening   |   Shop Instruments   |   Consulting Services   |   Elevated Body Temperature FAQs   |   Elevated Body Temperature White Paper

1. What is an elevated body temperature (EBT)?

An adult’s body temperature will typically range between 97.5 to 97.9 degrees Fahrenheit and vary throughout the day, though 99°F is still considered normal. Temperatures measuring higher than 100.4°F are considered an elevated body temperature or a fever.

2. Can EBT only be detected with a thermometer?

Thermometers accurately measure body temperature, but there are also non-contact screening tools, such as telethermographic systems, available to identify the surface temperature of skin. Telethermographic systems are also known as thermal imaging systems or thermal imaging cameras. They can serve as effective tools during initial temperature-screening assessments.

3. Does an EBT mean the screened individual has a fever?

If an elevated body temperature is detected using a thermal imaging device, the person’s temperature will need to be taken with a clinical thermometer to verify they do have a fever.

4. How does thermal imaging detect an elevated skin temperature?

Thermal imaging systems come with an infrared thermal camera and may have a temperature reference source. The cameras detect infrared radiation on the skin using sensors, compare it to a control group of temperatures, and convert it to a temperature reading. They also provide an image of body heat patterns on the skin.

5. What role does an elevated skin temperature have in identifying those with COVID-19?

Coronavirus Disease 2019 (COVID-19) has highlighted the need for accurate temperature screenings, especially within high-traffic settings, such as businesses, factories, and grocery stores. Screening for an elevated skin temperature is an initial defense against potential health risks, including COVID-19. Fever is a common symptom of COVID-19, usually appearing 2-14 days after exposure to the virus. However, it’s important to remember:

  • A fever does not necessarily indicate COVID-19.
  • A person with COVID-19 may not have symptoms or an elevated body temperature.
  • When thermal imaging detects elevated body temperatures, these reading should be verified through additional methods, such as by using a non-contact or contact thermometer.
6. Are there limitations to using thermal imaging systems in certain locations?

Yes. The systems are designed to screen people individually rather than in groups and to be used for initial assessment. The cameras should not be used for evaluating the temperatures of numerous people in crowds, which may be referred to as a “mass screening.” In critical environments such as nursing homes, other assessment tools may be more useful, since an incorrect measurement could result in residents being exposed to infection.

7. Do thermal imaging systems measure skin temperature accurately?

Scientific studies have demonstrated that when used correctly, thermal imaging systems generally measure surface skin temperature accurately, which is then used to estimate body temperature. The devices can be an option during this pandemic if more traditional temperature assessment products are unavailable due to high demand.

System accuracy depends on proper use, as well as properly preparing an individual to be screened for the process.

8. Does the FDA have a policy on the use of thermal imaging systems for body temperature screenings?

During the COVID-19 public health emergency, the U.S. Food and Drug Administration (FDA) is providing regulatory flexibility on the use of some telethermographic systems. The agency has issued guidance in order to help increase the availability of thermal imaging for initial body temperature measurements. This guidance relates to triage use during the current public health emergency, and the policy will be in place until the emergency ends. The policy applies to all thermal imaging systems that are intended for medical or temperature-screening purposes during the pandemic. It also outlines recommendations regarding system performance and labeling.

9. What types of device usage does the FDA policy cover?

The policy applies to devices that are used for initial temperature assessment and the triage of individuals for elevated temperatures in medical and non-medical environments. The FDA recommends that thermal imaging not be used to simultaneously measure the temperatures of people in crowded areas. The systems can serve as one method for initial temperature assessment in settings such as airports, corporate offices, factories, and stores. In other words, they can be a first step in an overall risk management process. In medical settings, a system could also be used to assess temperatures and determine the need for patient isolation until further evaluation.

10. Does the thermal imaging system have to be built for medical use?

There are products from leaders in temperature measurement that detect infrared radiation and convert these measurements into a body temperature measurement. Some camera manufacturers, such as FLIR, have registered products with the FDA for EBT screening purposes.

Normally, telethermographic devices that are regulated by the FDA are used for an intended medical purpose by health care professionals – and are labeled in this way. Telethermographic systems that meet the definition of a device under section 201 of the FD&C Act are regulated by the agency. However, with the pandemic, other devices which were not specifically built for medical purposes, may still be used for screenings due to the shortage of temperature-measurement devices.

11. What labeling should I look for on thermal imaging product to use it in a triage situation during COVID-19?

The FDA recommends that the device be labeled for medical use or for body temperature measurement for diagnostic purposes, including in non-medical environments. Each device should come with clear product labeling and performance information. The FDA also advises that thermal imaging equipment used in screenings may be tested and labeled according to the IEC 80601-2-59:2017 standard for medical electrical equipment. However, the agency is currently providing alternatives to this testing requirement, such as if the system meets criteria that includes:

  • A laboratory temperature accuracy, including the measurement uncertainty, which is equal to or less than ±0.5°C over the temperature range of at least 34 to 39°C.
  • An accurate blackbody temperature reference source.
  • Stability and drift of less than 0.2°C within a manufacturer-specified time period.
  • A device risk assessment that identifies potential safety issues.
12. Do thermal imaging devices need regular calibration?

Regular calibrations will be critical to ensuring your thermal camera or thermal imaging device is operating to the manufacturer’s specifications. An accredited calibration lab can calibrate your devices according to stringent quality processes. At Transcat, we can ensure that each thermal imaging device meets or continues to adhere to its regulatory standard – or to the specific performance requirements recommended by the FDA for its screening purposes during the pandemic.

Transcat has become the industry leader in the accredited calibrations of test and measurement instruments. We regularly provide services for FLIR, Seek, Fluke, AEMC, CorDEX, Testo, and other brands of thermal imaging equipment.

13. How will I know when to calibrate my thermal imaging equipment?

You should be able to get device performance specifications from the manufacturer – as well as information on the recommended calibration frequency. In many cases, this information will be included on the product labeling as part of FDA recommendations. Transcat can calibrate both handheld and fixed mount thermal cameras, using each manufacturer’s established methods.

14. What’s the advantage to these systems compared to oral thermometers during a rapid screening?

Non-contact infrared thermometers or oral thermometers require screeners to be close to the individual receiving a temperature check. But with thermal imaging, operators can remain at a safe distance during quick, initial assessments. The thermal imaging process may also be able to measure surface skin temperature faster than the typical forehead or oral thermometer. Following EBT detection by a thermal device, the person’s temperature can be verified using a digital or basal thermometer.

15. What should I consider when using a thermal camera to identify EBT?

When using a thermal imaging unit or camera, make sure:

  • The device is capable of screening for elevated skin temperature.
  • The equipment was set up according to instructions.
  • Proper testing of the equipment has been done, and the correct distance range is being used between the screener and the person being assessed. These distances will be determined by the camera manufacturer’s guidelines.
  • Screeners have received training in the equipment and screening process.
16. What factors can affect accurate thermal imaging results?

Environment, humidity, drafts, reflective backgrounds, and lighting intensity are some of the factors that affect the accuracy of thermal imaging results. It’s important to review any manufacturer’s recommendations on equipment use.

17. How does a thermal imaging system differ from a non-contact infrared thermometer (NCIT)?

Both thermal imaging systems and NCITs can measure surface temperatures without contact. However, an NCIT is used to measure surface temperature in one location, while a thermal imaging system measures temperature differences across multiple skin locations, resulting in a visual heat map with a reported body temperature on the thermal image.

18. How do I choose a thermal imaging camera for elevated body temperature screenings?

You will want an accurate product that allows you maintain a safe social distance. It should meet the current FDA guidelines for initial body temperature assessment. You will need a fast thermography device if it’s being used in a rapid screening application.

  • The camera should be calibrated for skin temperature measurement.
  • The thermal imaging tool should detect heat efficiently.
  • Equipment results should be easy to read.
19. Do some systems require a calibrated blackbody?

Yes. A calibrated blackbody is a tool that checks the calibration of an infrared temperature sensor. Your manufacturer will let you know if a calibrated blackbody is needed with your device. If it is, during evaluations the displayed image area should include the evaluated person’s entire face and the calibrated blackbody background.

20. How can Transcat serve as a resource for my organization’s EBT screening efforts?

Transcat offers a broad selection of thermal imaging cameras and systems as well as NCITs. We also provide high-quality calibration services for IR thermometers and thermal imaging devices. Our labs are accredited to ISO/IEC 17025 requirements and ready to provide rapid turnarounds during this time. Regular calibration will ensure that your equipment is measuring accurately and serving as a vital tool in identifying elevated body temperatures. We will work to support your initial EBT screening efforts to help you reduce infection risks.

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