A plug-in connector with a plug side and a connector side is provided, the plug-in connector comprising a housing, a frame, and at least one contact insert. The contact insert comprises sensors and a circuit board with electronics. According to prior art, the risk of overheating of the electronics, occurring inside the plug-in connector as a result of power dissipation, is a reason for the failure of plug-in connectors known to date. Embodiments described herein ensure heat dissipation via a cooling element so that overheating is prevented.