An apparatus for treating a workpiece, the apparatus comprising a first chamber configured to treat the workpiece at an elevated temperature, the first chamber including an opening for receiving the workpiece; a second chamber in operative communication with the first chamber, the second chamber including an opening for transferring the workpiece to and from the first chamber, wherein the first chamber opening is aligned with the second chamber opening, and wherein a selected one of the first and the second chambers comprises a gate valve configured to selectively open and close access to the first and second chamber openings; and a thermal isolation plate formed of a material effective to substantially prevent heat transfer from the first chamber to the second chamber, wherein the thermal isolation plate is disposed about the first and second chamber openings in a sealing relationship.