Infrared radiation is an electromagnetic wave. Electromagnetic waves are produced by the interaction of electric and magnetic fields. The sun emits a variety of electromagnetic waves ranging from gamma rays to radio waves. The wavelength range of 0.75 to 1000 micrometers (μm) is called infrared radiation. Longer than this, the wavelength range of 4 to 1000 μm is known as far infrared radiation. Converted to temperature, this ranges from 450°C to -270°C. That is, the electromagnetic waves emitted by relatively low-temperature radiators are referred to as far infrared radiation.