Infrared rays are the only type of light wave of the solar spectrum which has a positive impact on the human body. In fact, they are necessary for human existence and not only.
Infrared rays are invisible to the human eye because they are outside our visual spectrum. This invisible light is absorbed by the human body and we feel the heat it causes.
It is the temperature difference we feel if we sit directly in the sun or in some shade. Even though we are in the same outdoor space if we sit in the sun we feel a higher temperature than when we sit in the shade. This is because infrared rays are blocked by the shade. Despite the shading, we warm up again because the infrared rays are absorbed by the surrounding objects and through their radiation, the heat reaches the person as well.
Infrared heating is a natural phenomenon and the human body itself is a source of infrared radiation. Make an example by briefly joining your palms together. Now they are separated from each other by about 1 centimeter and you will feel the heat they emit.
