A thermal cutoff is a safety device designed to prevent overheating in electrical appliances and systems. It works by interrupting the electrical circuit when a certain temperature is reached, ensuring that the device does not become a fire hazard. This mechanism is commonly found in appliances like toasters, hair dryers, and space heaters. When the temperature exceeds the preset limit, the thermal cutoff activates, cutting off power to the device. Once the temperature drops back to a safe level, the device can often be reset manually or automatically. This feature is crucial for maintaining safety and preventing damage to both the appliance and surrounding areas.