Far infrared rays have strong penetrating power and radiation power, and have obvious temperature control effect and vibration effect, which are easily absorbed by objects and converted into internal energy of objects. After being absorbed by human body, far infrared rays can make water molecules in the body vibrate, activate water molecules and enhance their intermolecular binding force, thus activating biological macromolecules such as protein and making biological cells at the highest vibration level. Due to the vibration of biological cells, far-infrared heat energy can be transmitted to the deeper layer of human skin, and the temperature below the deep layer rises, and the generated warmth is emitted from the inside out. The intensity of this effect can dilate capillaries, promote blood circulation, strengthen metabolism among tissues, increase the regeneration ability of tissues, improve the immune ability of the body, and adjust the abnormal excitement of the spirit, thus playing a role in medical care. Generally speaking, the infrared rays emitted by the heat sources of fuel combustion and electric heating appliances are mostly near infrared rays. Because of their short wavelength, they produce a lot of thermal effects, which will cause skin burns and lens damage after long-term irradiation. Other electromagnetic waves with shorter wavelengths, such as ultraviolet rays, X-rays, and gamma rays, will dissociate electrons on atoms, which is more harmful to human body. On the other hand, the far infrared ray has a long wavelength and relatively low energy, so the danger of burning is relatively small when it is used.