A distributed temperature sensing (DTS) system is operated to detect fluid leaks from a pipeline. The DTS system obtains temperature profiles from a sensing element that is deployed along the pipeline, where the profiles are temperature measurements as a function of distance. The temperature profiles are examined to identify the presence of a characteristic temperature signature expected to occur in the presence of a leak. A leak condition signal for a particular distance point is generated based on a determination that the energy of the temperature signal exceeds a threshold energy for that point.