Infrared therapy gets its healing ability from far infrared rays (FIR), which are light rays at the far end of the infrared spectrum. Infrared rays, when in contact with the human body, penetrate the body up to eight inches and turn into heat, warming the body from the inside out. This is not a contact heat, it is a deeply penetrating warmth that can raise the body's temperature, producing a false fever.
This false fever supports your immune system like a fever would during a cold or flu. Only, because you aren't really sick, the immune system is boosted and fights any other problem with your body, making the body healthier. It has been proven that raising the temperature of your body by one degree can boost your immune system by 40%.
At the same time, the warmth from the infrared rays increases blood circulation, getting nutrition to the cells in your body faster while eliminating toxins and waste quicker too.