Abstract: Methods for weld monitoring and for laser heat treatment monitoring are provided using infrared emissions. In the method for weld monitoring, an infrared (IR) signature emitted by a hot weld surface during welding is detected. The detected infrared signature is compared with a steady state infrared signature signal. The compared results are correlated with a predetermined weld parameter. The predetermined weld parameter includes at least one of a full penetration weld, a workpiece misalignment, and a workpiece contamination. In the method for monitoring a laser heat treating process, an infrared (IR) energy signal emitted by a workpiece surface during the laser heat treating process is detected. The detected energy signal is compared with a predefined voltage range. The compared results are correlated to identify a potential defect.