A smoke and temperature detection system includes a plurality of fiber optic cables terminating in a plurality of nodes positioned to monitor a fire or smoke condition at one or more protected spaces, and a temperature detection fiber optic cable having a plurality of fiber Bragg gratings arrayed along the temperature detection fiber optic cable. A control system is operably connected to the plurality of fiber optic cables and to the temperature detection fiber optic cable. The control system includes a first light sensitive device configured to receive a scattered light signal from the plurality of fiber optic cables, and a second light sensitive device configured to receive a reflected light signal from the fiber Bragg gratings. The control system is configured to detect a temperature at the fiber Bragg gratings based on one or more properties of the reflected light signal received at the second light sensitive device.