A connector device, for a temporary cardiac pacing wire, includes a conductive adaptor and a cover section which completely electrically insulates the adaptor and environmentally isolates it. The conductive adaptor comprises a contact receiving end having an aperture therein and a plug portion for plugging into a suitable medical instrument. The cover includes two clam shell sections attached by a hinge and a plug cover connected to one of the clam shell sections. In a first mode, the electrical cover completely surrounds the conductive adaptor and is locked in place so that it is secure and the plug cover is in position over the plug to completely insulate and isolate the conductive adaptor from the outside. According to a second mode, the cap is selectively removed from the plug but the two cover sections remain in place so as to expose the plug for use for connecting to medical instruments. The invention completely electrically insulates and environmentally isolates the conductive adaptor from the exterior when used in either of the two modes described.