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Entry Scan IR

Keep your workplace safe!

Stockton Infrared Thermographic Services logo
Entry Scan IR logo

Entry Scan IR

Keep your workplace safe!

Stockton Infrared Thermographic Services logo
Entry Scan IR logo

Entry Scan IR

Keep your workplace safe!

Stockton Infrared Thermographic Services logo
Entry Scan IR logo

Entry Scan IR

Keep your workplace safe!

Here are some FAQs to address your concerns

What is COVID-19?

SARS-CoV-2 is the novel coronavirus that causes coronavirus disease 2019 (COVID-19).

What does COVID-19 have to do with Fever Screening? 

On April 16, 2020 the White House and Centers for Disease Control (CDC) came out with:

Opening Up America Again

as guidance for US citizens and US companies in three phases to safely reopen the United States. In all three phases, employers are asked to do temperature checks on employees and visitors. This means Fever Screening.

What is Fever Screening?

Taking the temperature of humans to make sure they do not have a fever before they enter a building. Officially, it is called Human Febrile Temperature Screening.

What is a definition of a fever, what do fevers have to do with infections in general – and COVID-19 virus in particular?

Normal core body temperature average is 37°C or 98.6°F. A fever is considered any core temperature above 38°C or 100.4°F. Infections cause the body’s temperature to rise. The most common symptom (found in 99% of symptomatic cases of COVID-19 viral infection) is a fever.

What are the standards for setting up check points to accomplish fever screening at the entry points of buildings?

There are no official specific standards for check points, only physical distancing guidance that suggests that everyone be separated by 6 feet and people are screened for fever before entry to the building is granted.

What types of check points work best to accomplish Fever Screening at the entry points of  buildings and what does that have to do with thermal infrared imaging? 

The best is a two-part approach: Primary Fever Screening -using thermal infrared measuring of skin temperatures, and Secondary Fever Screening, using thermometers.

  • Primary Fever Screening: Since there is a relationship between the internal and external body temperatures of humans, it has been determined that; a) to reduce screening times, and b) to reduce the risk of cross-infection between the incoming person and the screener, that thermal infrared measuring of the skin on the face (specifically the inner canthus of the eye or tear ducts area) has an acceptable level of accuracy and repeatability to be used confidently as a primary screening method of fever screening. So in the primary fever screening process, when people with a skin surface temperature higher than that of a given set point are found by using thermal infrared methods, this apparent elevated body temperature warrants that person should be directed to Secondary Fever screening, using thermometers to determine if they actually do have a fever.       
  • Secondary Fever Screening: This is accomplished by checking the internal temperature of a human being by placing an analog or digital thermometer in the mouth, armpit or rectum. Also, tympanic thermometers (infrared ear thermometers) have gained popularity because they are mostly accurate, more non-contact and faster than other types. If the person has a fever, they are denied access to the building.
If infrared works, why not just get a bunch of temperature guns at Home Depot and let the guards check everyone coming through the gate? 

Here are a bunch of good reasons:

• First, temperature guns (spot radiometers) are notoriously inaccurate.

• The screener and the person entering the building would have to violate the 6-foot stand-off distance guidance because spot radiometers must be closer than that to read a temperature anywhere near accurately, which risks cross-infection. Also, with respect to the laser on many spot radiometers – the laser is just a guide and does not represent the exact spot or area where the temperature is being taken.

• The screeners would have to be extremely well-trained and would have to execute a perfect procedure every time in order to have any sort of repeatable results.

• The environment where the temperatures are taken would have to be at steady state, meaning that the people and the room where the screening takes place cannot be outside at the gate or in any unconditioned space.

• This is an extremely slow and inaccurate process, especially in a facility any larger than a 20-30 people/hour traffic flows. Imaging systems can handle 400-500 people/hour and document the results.

• Issues for your company:

o This unprofessional method will show that the company is not serious about reducing the risk of infection in their buildings.

o There is ZERO documentation of the temperature of every person screened each day. When an employee sues the company because they were infected with the COVID-19 virus at work, a diligent company will have image records and complete documentation showing that each person passed the fever test on each entry to the building -and the time when they did not and were denied entry. This can only be documented with a thermal infrared imaging system, connected to a computer.

There has been a lot of confusion about naming the thermal imaging part of fever screening, i.e., skin temperature measuring, elevated body screening, etc. What is a good definition of how thermal imaging is tied to any official terms? 

International and US protocols recognize Thermal Infrared Imaging as a valid method of detecting Elevated Body Temperature in humans by using Skin Temperature Measurement which will significantly speed the process of employees and visitors safely entering buildings by using Human Febrile Temperature Screening.

Who regulates Fever Screening (Human Febrile Temperature Screening) in the United States?

In the United States, the US FDA “clears” medical devices (they do not approve them). As it relates to thermal imaging: if a company wants to market a medical device, the company must obtain, submit, have evaluated and get 510(k) clearance for that device. In the past, many companies have obtained 510(k) Clearance, entitled: ‘Applications for Medical Device Product Code “LHQ” (System, Telethermographic (Adjunctive Use))’.

What, if any, ISO standards are cited in the FDA 510(k)?

The main two ISO standards related to the US FDA 510(k) documents are:

  • ISO/TR 13154:2017 – ‘Medical electrical equipment — Deployment, implementation and operational guidelines for identifying febrile humans using a screening thermograph’.
  • IEC 80601-2-59:2017 – ‘Medical electrical equipment — Part 2-59: Particular requirements for the basic safety and essential performance of screening thermographs for human febrile temperature screening’.
If many companies have obtained 510(k) Clearance, which companies have approval specifically for Human Febrile Temperature Screening?

Only two companies have FDA Clearance specifically for Human Febrile Temperature Screening for some (not all) of their series and/or models:

  • Infrared Cameras, Inc. (ICI)

Note: Clearance is for imager, including a blackbody complete system.

  • FLIR Systems, Inc. (FSI)

Note: Clearance is for imager only

If the FDA regulates the marketing and sale of medical devices and adjunctive devices and procedures, and there are only two companies that have obtained FDA clearance for Human Febrile Temperature Screening, why are there hundreds of companies currently selling devices for Fever Screening?

Because on April 16, 2020, the FDA Center for Devices and Radiological Health, Office of Product Evaluation and Quality released a document entitled:

Enforcement Policy for Telethermographic Systems During the Coronavirus Disease 2019 (COVID-19) Public Health Emergency’.

The document relaxes FDA regulations on the marketing and sale of Telethermographic Systems for medical use. In the document, the FDA uses words “recommends” and “should” throughout, and not the word “shall”. So, until the FDA withdraws this guidance and goes back to pre-April 16, 2020 standards, all manner of equipment and procedures are available to the public -sort of Carte Blanche to sell any and all “heat thingies”.

Why would the FDA relax the standards?

Many standards have been relaxed during this “Public Health Emergency” -not just this one. Below, our assumptions, based on much reading about this subject:

  • We assume that FDA was worried that the existing IR imager stock in the US would not meet demand (that was certainly true).
  • It would have been too time-consuming and/or too complicated for them to sort through all the documents in a short period of time and figure out how to relax the guidance just a little, in order to allow established companies to help meet the demand.    
  • We like to think, some of the above, but also because they wanted to open the flood gates to stimulate innovation and at the same time introduce competition to drive prices down for the consumers.

But we do not know.

When will the FDA Enforcement Policy for Telethermographic Systems be reinstituted?

Again, we do not know, but reading on the FDA web site, there are many references to keeping the current policies until at least the end of the “Public Health Emergency”, which again, from the web site, will be at least December 31, 2020. We anticipate that the “New Normal” operations for companies will include fever screenings for months or years to come.

What are some of the different types of entry point systems available?
  • Spot Radiometers
  • Single-Entry Point
  • Kiosks
  • Stand Alone IR Camera
  • High Flow Systems
Spot Radiometers

Maximum Traffic Flow – Best Use:

30/hour, Single small operations




Very inaccurate and zero documentation

Single-Entry Point

Maximum Traffic Flow – Best Use:

30/hour. High security bldgs./small offices


High security but could also be used in small offices.


Must be integrated into the existing security system.


Maximum Traffic Flow – Best Use:

50/hour. Small to medium operations


Looks modern.


Expensive, given what is inside the box.

Stand Alone IR Camera

Maximum Traffic Flow – Best Use:

100/hour (varies). Small to medium operations


Flexible designs at moderate cost.


Image quality, size, capabilities and documentation are variable

High Flow Systems

Maximum Traffic Flow – Best Use:

500/hour. Medium to large operations


Higher quality w/100% documentation


Higher cost and takes staff to operate the system.

Since our company may be purchasing many thermal infrared imaging systems for the purpose of fever screening and the fact is that this will become an SOP for many companies far into the future – past the emergency period – should we buy only FDA-cleared equipment? 

Here are some considerations you should take before moving forward with any purchases:

  • There are many different types of systems, one size does not fit all and cheap is not necessarily better.
  • Even the most expensive systems on the market will not make a big difference in the overall cost of your program.
  • Supplies [as of mid-May 2020] for thermal imaging systems of any kind are extremely low. Many companies are estimating 90 days minimum for delivery. So, availability is a huge factor. If you cannot get an imaging system for three months, you should get one that you can get and live with it for as long as you need to.

The bottom line is that the selection of the imaging system is best done for you by a consultant, who will have the better handle on which, how many and the type of IR imaging systems that will be needed to accomplish the goals that you set in your policy, considering; budget, entry points, traffic flows, shift schedules and other logistical considerations at a single entry point, a particular site or across the entire corporate inventory of facility stock.