What is FIR?
Fir stands for ‘far infrared’ light. FIR is electromagnetic radiation that is considered long wavelength infrared. FIR waves are thermal. This means that heat given off by the sun, lights, or a fire emits FIR waves. However, FIR waves are invisible to the naked eye; an infrared camera must be used to see them.

In fact, although they naturally exist in the sun’s spectrum, they were not discovered until 1800 by Sir William Herschel. Most of the sun’s energy comes from infrared rays, and approximately 80% of the sun’s energy is actually FIR waves. The FIR waves in the sun are considered to promote health and good body function.

FIR is close to the microwave region of the electromagnetic spectrum The International Organization for Standardization (ISO) states that FIR has a wave length of 50 – 1000 µm. However, astronomers typically consider it to have a wavelength of (25-40) to (200-350) µm. Still other groups may have other standards.
The FIR laser, also called the terahertz laser, is a laser that implements the FIR wave length of 30 – 1000 µm. It is one of the available sources of terahertz radiation. FIR lasers are used for detecting explosives and other chemical warfare. FIR lasers have helped with: terahertz time-domain spectroscopy, terahertz imaging, and diagnostics in fusion plasma physics.

FIR has become increasingly popular in the use of general health. It is believed to have numerous applications and benefits. It can be used to improve: blood circulation, flexibility of muscles, and the immune system. Additionally, it can be used to reduce stress or even relieve physical pain, such as joint pain. It also can be used for more spa-like applications: burning calories, removing toxins from the body, and even deep cleaning skin. There are many more claims that are made about the benefits of FIR.