A heat and AC thermostat is a device that is used to control the temperature of a room or building. It works by sensing the temperature of the air in the room and then turning on the heating or cooling system when the temperature reaches a certain level. The thermostat is typically set to a desired temperature and then it will turn on the heating or cooling system when the temperature reaches that level. The thermostat can also be programmed to turn on the system at certain times of the day or night, allowing you to control the temperature in your home or office even when you’re not there. Heat and AC thermostats are an important part of any home or office and can help to keep your space comfortable and energy efficient.