What is the main effect of infrared waves on human skin?

The main effect of infrared waves on human skin is that they are detected as heat energy. When infrared radiation comes into contact with the skin, it is absorbed and causes the molecules in the skin to vibrate more rapidly, which increases the temperature of the area. This sensation of heat is a fundamental characteristic of infrared waves, as they primarily transfer energy in the form of heat.

While some infrared therapy may have health benefits, such as enhancing healing processes, the direct and immediate perception of infrared waves by the skin is experienced as warmth rather than any therapeutic effect. Consequently, the response to infrared radiation is primarily a thermal one, making the detection of these waves as heat energy the correct answer.