A method for the thermal management of a fuel cell, which method comprises: processing a fuel supply stream in an autothermal reformer to produce a fuel cell supply stream comprising a concentration of methane; and reforming within the fuel cell methane present in the fuel cell supply stream, wherein the concentration of methane in the fuel cell supply stream is controlled by operation of the autothermal reformer in order to achieve a desired level of reforming of methane within the fuel cell.