Panel heaters work by heating a large infrared surface made of stainless steel, ceramic, quartz cloth or high temperature glass, with quartz cloth heaters being the most common type. Because the heating occurs over a larger area than with other types of space heaters, there is less chance of uneven heating. Their constant temperature ensures the outside of the unit does not reach the extreme temperatures experienced with other types of space heaters, thus reducing the chance of being burned with this type of heater over other types.