A new method of using fiber Bragg gratings as the sensing elements in the measurement of temperature rises of electrical appliances is proposed in this paper. Comparing with the conventional measurement method with thermocouples, the new method can overcome problems such as electromagnetic interference, hazard of electrical leakage, etc. The characteristics and key components employed in the measuring system are analyzed and discussed. The experimental results show that the temperature rises of electrical appliances under test can be obtained quickly and accurately with the specifically designed sensors made by optical fiber Bragg gratings.