Abstract: A fiber-optic temperature sensor assembly comprises a cap with an inner cavity. A sensor member is received in the inner cavity of the cap. The sensor member has light-transmitting properties adapted to change with temperature variations. An optical fiber has a first end received in the inner cavity of the cap, and a second end of the optical fiber being adapted to be connected to a processing unit for transmitting light signals between the sensor member and the processing unit. A pressing device is received in the cap and pressing against the sensor member such that the sensor member is in operational contact with the first end of the optical fiber for transmission of light therebetween during operation of the fiber-optic temperature sensor assembly.