Quartz heating is a type of radiant heating used throughout the foodservice industry in equipment of all kinds. Radiant heating uses infrared waves to directly heat the surfaces of foods in holding cabinets, heated merchandisers. All objects emit and absorb infrared heat, which is part of the electromagnetic spectrum with a frequency below visible light. Hotter objects will radiate more of this heat. This is the basis of the technology for most quartz heaters. In restaurant equipment, quartz heaters are tubular and may be controlled by a timer.