Far-infrared or radiant heat (FIR) is part of the natural light spectrum of sunlight and a safe form of energy that heats objects by a process called direct light conversion. Radiant heat warms the objects around it without affecting the temperature of the surrounding free air. All warm-blooded animals emit far infrared/radiant heat, a beneficial and essential form of energy that has the ability to penetrate, refract, radiate and reflect.
Infrared heat is divided into three wavelength categories: near, middle and far infrared, which are measured in microns or micrometers. The sun produces most of its energy output in the infrared segment of the spectrum. Our atmosphere allows infrared rays in the 7-14 micron range to safely reach the earth’s surface. When warmed, the earth radiates rays within this band, with its peak output at 10 microns.
Near infrared or close heat (.076~1.5 microns), is extremely hot and used industrially for curing paint, setting glues and many other applications. Middle or intermediate infrared heat (1.5~5.6 microns), is a visible red light that is not meant to be used at close range. It is utilized in food warming lamps and also has some medicinal benefits. Far or long wave infrared heat (5.6~15 microns), is invisible to the naked eye and used in many medical applications, from incubators to physical and dermatological therapies, and is the only heat known to lower blood pressure. Far infrared rays offer the most health benefits because they are capable of penetrating 2-3 inches into the human body, where they gently elevate the body’s surface temperature, increase circulation, nourish damaged tissue and activate major bodily functions
When FIR heat penetrates through the skin to the subcutaneous tissues, it transforms from light to heat energy, dilating blood capillaries and assisting the body in eliminating toxins and metabolic wastes through sweating. Activated by heat, the FIR energy is absorbed by human cells in a process known as “resonance” or “resonant absorption”. Cellular activities are instantly invigorated, resulting in improved metabolism. Far infrared lamps are used by doctors, chiropractors, physical and massage therapists and acupuncturists in the treatment of arthritis, joint pain, stiff muscles, injuries to tendons and ligaments and to promote faster bodily healing. According to Dr. Tsu-Tsair Oliver Chi, tissues needing a boost in their output selectively absorb FIR rays.
Thermal therapy has been in existence for thousands of years, dating back to ancient civilizations such as the Romans, the Chinese, the Finns and the American Indians.