Disclosed is a preferred mold design for producing plastic, molded preforms, which may be blow-molded into a container of a final, desired shape. A preferred mold includes a temperature control system for maintaining the preform mold at a desired temperature. The temperature control system can pass fluid through channels within the preform mold to cool plastic that is injected into the preform mold. In some arrangements, a mold comprises a neck finish mold, the neck finish mold configured to transfer heat away from the molding surface toward a channel conveying a working fluid. A heat transfer member may be at least partially positioned within the channel to transfer heat to the working fluid. In some embodiments, the mold comprises a high heat transfer material.