How reliable are thermal scanners?

By George N. True II

It’s has become an important part of the new normal nowadays. Before entering any establishment, people are usually checked by security personnel with the help of thermal scanners.

This portable device that looks like a small gun is pointed at the forehead or above the eye level to record a person’s temperature. It has an infrared sensor that quickly measures heat from the body’s surface without touching the skin.

The New York Times said the use of “thermometer guns” is common during viral outbreaks. In the early 2000s, they were widely used to stop the spread of SARS in China. A decade later, they appeared in West Africa during the Ebola outbreak.

Today, this device is making a comeback because of the COVID-19 pandemic. By measuring body temperature, the thermometer gun helps detect “sick” people (those with fever) and prevents them from entering an establishment where they can infect others.

Wrong readings

In theory, that sounds like a good idea, but some health authorities aren’t impressed. That’s because a high temperature doesn’t necessarily mean someone is sick or has the virus.

In fact, they point out that thermal scanners usually give wrong readings. This happens when the device is held too close to the person’s forehead (which results in high readings), or far (which gives low readings).

Thermal scanners also give wrong readings if they are used in dusty places, on a person who has been exercising or running, or has taken certain medicines to lower fever, according to Jim Seffrin, infrared devices expert at the Infraspection Institute in New Jersey.

Overrated

Dr. James Lawler of the University of Nebraska’s Global Center for Health Security is another person who believes that thermometer guns are overrated. He said they are “notoriously not accurate and reliable” and used mainly “for show.”

Lawler revealed that when he visited West Africa during the Ebola outbreak, he was frequently checked with thermometer guns outside hospitals or at roadside checkpoints. His recorded temperature was so low which meant that he was dead – something Lawler questioned.

Even if the devices are accurate or used properly, experts point out that thermometer guns may not catch infected people. The New England Journal of Medicine said those with COVID-19 may have fever only after several days, and they can always hide it with medicine.

Big business

However, these criticisms have not stopped people from using thermometer guns. Because of the pandemic, the demand for these devices has grown considerably, causing shortages across the world, according to the Times.

Many devices, which have become more expensive, are made in China. The Times reported that one Chinese manufacturer makes 2.5 million thermometer guns yearly for government and private customers.

Business is so good that prices have increased fivefold. The global thermal scanners market is expected to reach $6.7 billion by 2025, not bad for what was once a small industry.

A manufacturer in Shenzhen, China, said thermometer guns are normally used indoors to check a baby’s temperature, but they have become so popular that they are now being used everywhere.

Of course, not everyone knows that. Even now, ignorance is bliss, but that can have dire consequences in those who know better.

For questions, email georgenavatrue@yahoo.com.