Having access to correct information is paramount in combatting the COVID-19 epidemic. Sadly, all it takes is one rumor to create uninformed hysteria. Disinformation can cause panic and cause people to make really bad decisions when it comes to their health. Wearing a mask, for instance, has become a major political and health issue. Of course, neither of these should have been the case. We wear seatbelts and we don't have much a problem with worrying about our freedoms and there is no scientific evidence that wearing a mask harms the wearer. This is obviously true as hundreds of thousands of healthcare workers would have been dead already over the last 100 years since their inception. Yet, these ideas persist.
The latest ill-informed scare has come in the form of private social media. Instant messages from family and friends are warning people that getting your temperature checked can cause cancer. Some people are refusing to get checked citing that they don't wish to get a brain tumor.
This scare is unfounded. The devices do not emit any waves. The confusion is in the understanding that infrared electromagnetic waves are involved with this technology. However, the forehead temperature reading device is not sending waves out, it is receiving waves. Just as a radio or television can be tuned to receive certain frequencies, the forehead thermometer is tuned to detect the frequencies emitted by warm bodies.
So, can forehead thermometers can cause brain tumors? No. They only receive waves, not send waves into someone's brain.