Infrared energy is the frequency range on the electromagnetic spectrum that falls immediately below visible red light. The body's tissues normally produce infrared energy (which is why people can be seen on infrared cameras) for warmth and tissue repair. Infrared energy can penetrate the body more than an inch to provide heat deep in the body where it is needed. Conventional heating systems only heat the air around the body.

Infrared is the energy behind the warmth we feel from the sun, even on cold winter days.
In the wintertime, we feel we need to wear a sweater in order to be comfortable in a room with an air temperature of 18C (70F) However, in the summer time, we feel comfortable with short sleeve shirts and shorts with the same air temperature. Why is this? It is because the infrared waves heat the objects around us and this heat radiates and warms our bodies. We’re warm on the inside.

Infrared waves are thermal. In other words, we experience this type of infrared waves every day in the form of heat! The heat that we feel from sunlight, a fire, a radiator or a warm sidewalk is infrared. The temperature-sensitive nerve endings in our skin can detect the difference between inside body temperature and outside skin temperature.