This paper aims to examine the thermal influence of a resistance spot welding process (extrinsic joint) on a nearby joint of a thermoplastic and a metal sheet (intrinsic joint). Parameters considered in this study are the distance between the spot weld and the intrinsic joint, the welding current, and different material thickness pairings. The influence is investigated using single-lap shear (SLS) specimens. A numeric simulation of the spot-welding process is used to predict the resulting temperatures in the intrinsic joint. An experimental study indicates the influence of the resistance spot welding process on the compression shear strength of the intrinsic joint.