Despite humans' narrow thermal comfort range, most traditional heating systems have simple controls.  A wall thermostat compares actual ambient temperature to desired temperature and turns the heat supply on or off to maintain desired temperature plus or minus a degree or two.  Because ambient temperature has "inertia" and does not change rapidly this "binary" control meets our thermal comfort needs.

Lighting systems often have more sophisticated controls.  Individual fixtures or banks of fixtures may be turned on or off or dimmed depending on personal preference, amount of sunlight entering the room, presence or absence of an occupant, etc.  Unlike ambient temperature, light has no "inertia" and the light intensity changes immediately with light output. Too much light is immediately wasted and the energy saved by turning the lights down or off when not needed justifies the investment in controls.

Radiant heat is somewhere between conventional heating and lighting.  The ambient temperature increase resulting for infrared absorption and re-radiation has "inertia" but the thermal comfort effect of direct infrared radiation, which is significant, changes immediately with infrared output.  As with lighting, the energy saved by turning the HotZone™ heaters down or off when not needed justifies the investment in controls.

High intensity gas heaters are not very "dimmable" and tend to be on or off.  Thermal comfort can be achieved by overlapping the heaters' beam patterns and turning on or off a percentage of the heaters, depending on need.  High energy efficiency is achieved by turning off  heaters when they are not required for thermal comfort.

High intensity electric heaters are dimmable and while they are often used in an on/off mode, can be more finely adjusted to optimize thermal comfort.  High energy efficiency is achieved by turning the heaters down or off when they are not required.