Hot rail car bearings or wheels are identified by sensing an infrared radiation from the hot surface and determining whether features of the sensed signals are indicative of hot rail car surfaces. The features may include the signals themselves, with distances or correlations being established between the signals and signals of known hot bearings or wheels. The features may be analyzed in a feature or decision space, with boundaries being established that identify hot bearings or wheels, or that establish false positive features or noise. The identification may also be implemented as a matched filter.