I’ve heard of near, medium and far infrared. What’s the difference?

Near Infrared, sometimes known as “heat lamps” or “quartz heaters”, operate between 780 nm to 1,400 nm and emit temperatures of 1300°C. They produce a lot of heat and deeply penetrate body tissue. Prolonged exposure isn’t recommended and they shouldn’t be used for general heating in the home. Medium Infrared infrared heaters operate between 1,400 nm and 3,000 nm and emit temperatures of 500 – 800°C. Such heaters reach the temperature quickly and are commonly used in manufacturing and food processing. They are also used in large public and commercial heating, typically on ceilings where they cannot be touched and they are far away from people. Far infrared heaters, as provided by Warm4less, operate in the wavelengths above 3,000 nm – the therapeutic part of the sun’s spectrum. Surface temperatures are far lower at around 90°C, with no visible light. There is minimal penetration of human tissue, only to the outer epidermis, so avoiding the possible adverse health implications of prolonged use for near infrared