IO HVAC Controls Conceal-a-Stat was designed for use in areas you want to maintain a specific temperature while removing the risk of a wall mounted thermostat being tampered with, damaged, or stolen. Conceal-a-Stat controls unit heaters, cabinet heaters, in-will heaters, fan coils, and air conditioning unit. The thermostats common applications include use in hospitals, locker rooms, entryways, warehouses and hallways.