The article is from the public number: Nutshell (ID: Guokr42) , author: Li Xiaokui.

Affected by the epidemic, when people enter public places such as communities, subways, shopping malls,Have to take a temperature test. The instrument used by staff to measure body temperature is usually a gun-type thermometer, which can be used to measure body temperature by holding it against the forehead.

At least as far as I am concerned, I have encountered this situation more than once: the staff took a forehead gun to measure the temperature of my forehead and then the temperature of my wrist, and sometimes only the temperature of my wrist.

Isn’t it called the “forehead” warm gun? Is it OK to take a temperature measurement with the wrist?

Forehead gun may be inaccurate

Almost any object emits infrared light. The amount of energy contained in it is directly related to the temperature of the object. When a worker holds a forehead gun and clicks on your forehead, the sensor in the forehead gun can quickly measure the temperature of the forehead skin based on the infrared energy emitted from the forehead.

Screenshot from YouTube @ Vive Health

Avoid cross infection (without touching the subject’s body) , fast temperature measurement (After all, most people have bare foreheads) is the advantage of a forehead gun, so it is especially suitable for screening people with fever symptoms in a place with a large flow of people, which is safe and rapid.

But the disadvantages of forehead guns are also obvious .

Measuring measurement errors due to temperature and wind speed (such as the cold and windy days in the north, using a forehead gun outdoors may affect the measurement Accuracy) ;

Second, the skin temperature of the forehead exposed is not stable: a healthy person has just run 5 kilometers, and the skin temperature measured by the forehead gun is likely to be too high. It was blown for half an hour in the north wind. The value may be low. If the subject’s forehead is covered by hair, sweat, grease and dirt, it will also affect the reliability of the forehead gun degree [1] .

It’s not easy to be fast and accurate.

The take-out packaging of the previous few days is accompanied by the temperature of the staff involved in the take-out. The body temperature is so low, it is likely that it was measured by a forehead gun. 丨 Photo by the author

The gun is not allowed, what should I do?

For the problem that the temperature measurement of the forehead gun is easily affected by the environment, it can be solved by taking several measurements and taking the average value, or comparing the underarm temperature measured by the forehead gun and the mercury thermometer.

Specifically, you can do this:

1, make sure your temperature is normal;

2. Measure your body temperature with a forehead gun and take a reading, such as 36 ℃;

3. Measure the body temperature of the same part of another person. If the measurement result is significantly higher than 36 ° C, it is necessary to conduct a further examination of this person.

As for the problem of the forehead itself, it is recommended that the subject wait for a few minutes in the temperature measurement environment to measure, so that the body can adapt to the ambient temperature. Some manufacturers of forehead guns have suggested that in addition to measuring the forehead, you can also measure the abdomen, chest, and shoulder blades. For more stable temperature, please refer to [2] . But being forced to stop on the way, and to carry clothes in public, was not realistic for all parties.

Will a forehead gun measure the wrist?

A compromise, can you measure your wrist temperature quickly with a forehead gun?

At the press conference of the State Council ’s Joint Prevention and Control Mechanism held on February 16, Feng Luzhao, a researcher at the Chinese Center for Disease Control and Prevention, said, If you want to use a forehead gun to measure the temperature of people who enter indoors, or outdoors When taking a temperature measurement, it is best to measure the parts covered by clothing, such as the wrist or neck, the reading will be more accurate [3] .

In addition to clothing insulation, the temperature of the wrist itself is relatively stable. During the awake time, the temperature of the wrist changes around 1 ° C. [4] Compared with the forehead exposed to external wind and sunlight, the fluctuation is not too great.

So in this big winter, if you want to pass the examination at normal body temperature, but don’t want to delay time and take off your clothes, please trouble to roll up your sleeves and take a test.

A staff member took temperature measurements of passengers at the airport 丨 CNS photo / Reuters / Thomas Peter

What’s the point of this troublesome forehead gun?

There is a lot of trouble in using a forehead gun. Why use it?

Mercury thermometer for measuring underarm temperature (or electronic thermometer) It is cheap and accurate, but on the one hand it takes a long time to measure and on the other hand Because the measurement process contacts the human body, it needs to be disinfected after each use, which adds to the workload. In addition, if a mercury thermometer is broken, broken glass slag and harmful mercury (that is, mercury) .

Electronic thermometer 丨 Wikipedia

Another ear thermometer that reaches into the ear canal to measure the temperature of the eardrum is also more accurate, but it also has the problem of physical contact. It is possible to use a disposable protective cover on the ear thermometer probe, but it is a significant cost.

Using the ear thermometer 丨 Screenshot from YouTube @ Tommee Tippee®

For this reason, In the face of infectious diseases and a large number of susceptible people, the forehead gun is a cost-effective choice (These types What else is different about the thermometer? Click here to view) . During SARS in 2003, and during the Ebola outbreak in West Africa a few years ago, infrared thermometers, including frontal temperature guns, came in handy in the field of public epidemic prevention.

In September 2014, a Kenyan staffer was taking the temperature of primary school students Akintunde Akinleye / Reuters / Landov

Infrared human thermal imaging temperature measuring equipment commonly used in airports 丨 EPA

There are two more points to say.

First, the temperature measurement with a forehead gun in public places is only the first line of defense for screening for fever. To determine whether you have a fever, it is best to use a more accurate mercury thermometer or electronic thermometer, or take protective measures to go to the hospital’s fever clinic, and do not rely too much on the measurement results of the forehead gun;

Second, fever is not the only symptom of new coronary pneumonia or even other infectious diseases. You cannot take precautions such as hand washing, ventilation, and disinfection just because your body temperature is normal.



[2] “JXB182 Bealcon Electronic Thermometer Manual”


[4] Martinez-Nicolas A, Ortiz-Tudela E, Rol MA, et al. Uncovering different masking factors on wrist skin temperature rhythm in free-living subjects [J]. PloS one, 2013, 8 (4).

The article is from the public number: Husk (ID: Guookr42) , author: Li Xiaokui