Infrared radiation has wavelengths from 700nm to 1mm and is characterized by smaller bands. IR-A (near infrared) is the spectral region from 701 to 1400nm. IR-B includes wavelengths from 1.4 to 100mm. The IR-C spectrum is 0.1 to 1mm. Most radiative heat transfer involves the infrared region. Sources of infrared typically are sources of radiative heat, including fires and open flames, stoves, electrical heating elements, certain lasers, and many other sources.