Final answer:
Fuses and circuit breakers protect against excessive current, but they won't protect against overheating or burnout not caused by current issues.
Step-by-step explanation:
Fuses and circuit breakers are important safety devices in electrical systems that protect against thermal hazards by interrupting excessive currents. A fuse contains a metal strip with a low melting point that breaks the circuit permanently when overheated by an excessive current. In contrast, a circuit breaker is an automatic, restorable switch that uses a bimetallic strip to break the electrical connection when overheated. However, neither a fuse nor a circuit breaker will protect electric motors against overheating unrelated to excess current, such as that caused by mechanical failure or lack of cooling. They also do not protect against motor burnout or other issues not directly related to excessive current.