There are two main safety features. Overheating protection ensures that the heater turns off before it becomes dangerously hot to prevent a fire. Tip-over protection turns off the heater if it’s knocked over, preventing damage to surfaces. The former features on all of the models here, the latter isn’t available on all heaters. Typically, tip-over protection is best where it’s likely that a heater could get knocked over, such as with children or pets around.