Convenient Controls The design features two large knobs at the front that allow you to precisely adjust the thermostat and to switch between the high and low heat settings. This helps to ensure that you get just the right heat output for your space. Convenient Controls The design features two large knobs at the front that allow you to precisely adjust the thermostat and to switch between the high and low heat settings. This helps to ensure that you get just the right heat output for your space. Advanced Safety Features A tip-over cutoff switch automatically turns the portable electric fan heater off if it is knocked over to help prevent fires. The design also features a built-in sensor that shuts the heater off when it reaches an unsafe temperature to help prevent damage to the unit from overheating.