gas reforming which when the reformer is used in a fuel cell stack as in fig4 the reformer cools the hottest areas of the stack and improves temperature distribution this cooling of the hottest areas of the stack and improved temperature distribution is also aided by the baffle 6 which directs the flow of gas to particular areas of the reformer along the u shaped path to this end and as shown in fig2 for the reformer 100 as used in the cross flow stack 200 there is no catalyst in the inlet section 102 with no catalyst in this section excessive cooling of the stack 200 along the oxidant inlet face 204 of the stack which face is adjacent the inlet sections 102 of the reformers 100 is avoided because the oxidant that enters the stack 200 in the area of each of the inlet ports 4 of the reformers 100 has not yet undergone an electrochemical reaction the inlet sections 102 of the reformers can now act as a heat exchangers to warm the incoming unreformed fuel gas with heat from the oxidant inlet gas as also shown in fig2 catalyst distribution begins in a part of the turn section.