Can Thermal Cameras Detect Fever?

September 21, 2020

Thermal camera detecting human temperature

Can Thermal Cameras Detect Fever?

No, thermal cameras cannot detect what medical experts would define as a fever in an individual. What they can do is measure the skin temperature of any individual and in line with medical diagnoses, should it be above certain temperatures then there is a high chance the individual has a fever.

 

How Does A Thermal Camera Detect Skin Temperature?

Thermal image of women wearing mask

By capturing the infrared radiation emitted from human skin a thermal imaging device can calculate the temperature from level of emission. It also converts the radiation into visible images that we can interpret by using small devices called microbolometers. For each pixel on the screen of the thermal imager there is a microbolometer which will change its color to represent a temperature and into an image we can see.

 

What Is The Best Thermal System To Detect High Temperatures?

There is no one solution fits all in this scenario as the factors you need to take into account include;

  • Does it need to be staff operated?
  • How many people does it need to screen?
  • Will it be in a fixed location?
  • Does it need connectivity?
  • Does it need to store information?
  • Does it need to have alerts?
  • Does it need to take photos?
  • How much space do you have to work with?
  • How much is your budget?

Check out our post about coronavirus here

Arguably, many people would think about budget first, not at the last of the list. Especially since the factors before it all have an effect on the budget. We have put it at the bottom of the list because you need to first consider your own requirements and then decide if its within your budget, for example, let's say you have a budget of $20,000 and you purchased a state of the art thermal imaging system that tracks users with 4k screen, sounds an alert to staff should someone trigger the heat sensor and locks down the building. What if you only needed a system that scans 10-20 people per minute? Hand operated for 15 minutes in the morning and late afternoon and could sound alert the user just in case they missed someone? Finally, what if this system only cost a tiny fraction of $20,000. Then you would take the lower costing and more suitable option.

Please contact us with your requirements and we will assist and explain if our products are suitable. Contact us

 

How Best To Set Up And Use A Thermal Camera For Screening?

  • Whether the thermal camera is used on a tripod or handheld, they should be used at entrances and in an indoor location that reduces the chances of body temperature being affected by source of heat.
  • Screen people as they walk past, maintain social distancing.
  • Should the thermal camera alert the user to high temperature individuals, follow further screening procedures.

 

How Close Does A Person Need To Be In Front of The Thermal Camera?

For the thermal camera to give the most accurate reading, individuals should be as close as possible. However, with the intention of keeping social distance for the camera user too, there are thermal cameras that can maintain a high level of accuracy for up to 2.5 meters away.

 

How Accurate Are Thermal Cameras Compared to Non Contact Thermometers?

The majority of thermal cameras are designed for industry use and will have a large temperature range from -4 °F - 1832°F (-20°C - 1000°C) and more, but they come with an accuracy of 2% or +/- 2 °C while operating in room temperature of around 86°F (30°C). There are potentially issues with using these types of thermal cameras for screening high temperature with that level of accuracy since the difference between a fever and normal temperature is very low. As a result this accuracy is not suitable for fever detection in humans.

Newer thermal cameras made just for fever detection will have much greater accuracy at around 0.3°C which leaves very little room for error. In order to achieve this level of accuracy many different methods are used. Two common methods are; reducing the temperature range from -20°C - 1000°C to 32°C-42°C which enables the device to be more accurate at a much narrower range. The other commonly used method is to use a black body as reference for skin temperature screening, however, this method has its own advantages and clear disadvantages such as the high costs and problems of integrating this black body solution.

 

What Temperature Is Considered A Fever?

finger on thermal camera screen

Generally, temperatures above 100.4 F (38 C) can be considered feverish, this can vary slightly from person to person. However, if you are detected to have a body temperature of 103 F (39.4 C) or higher, you must seek medical attention immediately especially if you show other symptoms.

It's important to note that there are many normal events that can lead to a temporarily higher temperature and still not have any illness. This can be more prominent in individuals after exercise, walking in hot weather or even normal fluctuations from a woman’s monthly cycle.

Therefore, its recommended that should an individual be detected with high temperature you follow these guides;

No, thermal cameras can never be used as a device to diagnose if someone has coronavirus or any other illness. This is because the only function of a thermal imaging device is to detect temperatures and not make medical diagnosis. Having a high temperature on its own is not an absolute indication of an illness. 

Additional Questions

If you have any other questions relating to thermal camera, non contact thermometer and how they can be used to increase safety in your community please send us a message via Contact us



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