is It True that Infrared Thermometers Could Damage Brain?

Posts shared thousands of times on Facebook since the start of pandemic claim that using an infrared thermometer to take your temperature risks damaging the pineal gland, located in the brain. This is false, assert several neuroscience researchers who ensure that this type of thermometer does not emit infrared radiation when used.

According to these "testimonies", taking a temperature using an infrared thermometer endangers the pineal gland, located in the brain. These posts have been shared nearly 6,000 times on Facebook since last summer.

This is false: experts reveal details that "the individual tested is in no way subjected to exposure to infrared radiation during the temperature measurement ".

The thermometer actually captures infrared spectra emitted by the human body through a lens on a sensor. Depending on the wavelengths of the radiation received, it displays a higher or lower temperature.

Moreover, even if infrared rays were directed towards this gland, it is located too deep in the brain for them to reach it, according to  researchers in neuroscience.

"Light has a very low capacity to penetrate the barrier formed by the skull, even if infrared wavelengths penetrate more easily", they explain.

"We would have to cross the cranium completely to reach this small gland which is located at the bottom of the brain", abounds Mireille Rossel, teacher-researcher in neuroscience at the Ecole Pratique des Hautes Études (EPHE).

The genesis of this belief in the effect of the thermometer on the pineal gland comes from the fact that in reptiles and birds this gland is indeed just under the skull and contains photosensitive cells (and therefore sensitive to sunlight. visible and infrared spectrum). This is not...