A heat station for a GM or Stirling cycle expander provides a versatile, efficient, and cost effective means of transferring heat from a remote load at cryogenic temperatures that is cooled by a circulating cryogen to the gas in a GM or Stirling cycle expander as the gas flows between a regenerator and a displaced volume. The heat exchanger includes a shell that has external and internal fins that are thermally connected, are aligned parallel to the axis of the shell, and are enclosed in a housing having a single port on the bottom of the housing.