How reliable and accurate non-contact thermometers could save lives

Jul 14, 2020 | Temperature, Healthcare

If you haven’t had your forehead scanned with an infrared thermometer before entering a building recently, it will likely happen soon enough. From offices and stores to restaurants and entertainment venues, temperature screening at the door is just one of the many ways businesses and governments are working to reduce the spread of COVID-19.

How Accurate Non-Contact Infrared Thermometers Can Reduce Spread of COVID-19

The US Centers for Disease Control and Prevention (CDC) lists temperature checks as an “optional strategy” to decrease the risk of outbreaks. Because the CDC does not mandate the checks, it is up to states to determine temperature check requirements. In many states, temperature checks are mandatory at gyms and fitness centers, manufacturing facilities, restaurants, and retail stores. Other states require all employees to undergo daily temperature checks.

Who’s impacted by temperature screening?

Walmart and Amazon have been checking employee temperatures since mid-March, around the same time the Equal Employment Opportunity Commission’s Pandemic Preparedness in the Workplace approved the use of temperature measurement on employees. This approval was also backed up by the Americans with Disabilities Act.

Now schools are contemplating the use of temperature checks before students can enter—if the schools decide to open their doors at all. And airlines, most recently, have asked that the federal government require all passengers to have their temperatures checked prior to passing through TSA. Frontier Airlines has already taken temperature measurement into its own hands by checking passengers at the gate.

What constitutes a fever?

The adage that 98.6 °F is “normal” is more associated with a song than anything medically factual. According to the Cleveland Clinic, a study revealed that “the average person today actually runs a little cooler than [98.6 °F]—somewhere between 97.5 °F and 97.9 °F.”

So then, anything over 97.9 °F is a fever? Not quite. The “CDC considers a person to have a fever when he or she has a measured temperature of 100.4 °F or greater.”

What are the best ways to screen for a fever?

Just one inaccurate temperature reading can put people at risk for spreading COVID-19. So, it seems that temperature checks would be a simple and straight-forward method to use—take the temperature of every individual before entering, determine if they have a fever, and provide guidance to that individual. Everyone with a fever is sent away, and those without can enter.

The effectiveness of temperature checks depends on the device and conditions under which it is used. Here are the four primary ways to capture human temperature.

  1. Oral digital thermometers: the most accurate, but not practical for screening large numbers of people
  2. Ear thermometers: can be accurate but are prone to error due to things like ear canals blocked by wax
  3. Non-contact forehead infrared thermometers: can be accurate, but are prone to inconsistency due to ambient temperatures, sweat, dust, or water
  4. Infrared thermal cameras: can be used to move people through screening more quickly; works as an alarm system for temperatures detected that exceed a predetermined threshold

A CDC guide on identifying sick workers has recognized non-contact, self-administered screenings as providing the lowest risk of spreading COVID-19. As this is not practical in most scenarios, the U.S. Food and Drug Administration has identified non-contact infrared thermometers as the next best bet. The primary issues identified by healthcare professionals regarding non-contact infrared thermometers has been around accuracy and repeatability.

What to look for in a non-contact infrared thermometer for humans

Most IR thermometers use a single-point temperature measurement system. This creates the chance for false negative readings. These types of thermometers often need to come to an ambient room temperature before they can be close to accurate. They also suffer from temperature drift over time and could be susceptible to interference from other nearby devices. The majority of IR thermometers in the market today have not been drop tested to withstand the most common of human faults, nor do they have a “body” mode to offset from human skin to internal body temperature.

Fluke has engineered a consistently repeatable, reliably accurate temperature measurement tool. Coming soon, the new Fluke non-contact infrared thermometer is accurate down to the 0.5° F, even in ambient temperatures as hot as 104 °F, or as cold as 59 °F.

The Fluke infrared thermometer for humans is ready to use as soon as it is turned on and uses a SCAN feature to ensure a true measurement. The user simply moves the thermometer in an arc over the forehead. The thermometer reads all temperatures in the scan and shows the highest measured as the result. The SCAN feature also reduces the possibility of any interference from sweat, dust, or water.