A thermal fuse is a safety device designed to prevent overheating in electrical appliances. It works by breaking the circuit when a specific temperature is reached, stopping the flow of electricity. This helps to avoid potential fires or damage to the appliance. Typically found in devices like toasters, hair dryers, and washing machines, thermal fuses are usually made of a heat-sensitive material. Once activated, they cannot be reset and must be replaced to restore the appliance's functionality. This simple yet effective component plays a crucial role in ensuring user safety.