Described herein is a fuel processor that produces hydrogen from a fuel source. The fuel processor comprises a reformer, boiler and burner. The reformer includes a catalyst to facilitate the production of hydrogen from the fuel source. A boiler heats the fuel source before receipt by the reformer. The burner provides heat to the reformer and to the boiler. The fuel processor may also comprise a dock that maintains position of the reformer and boiler within the fuel processor. Dewars are also described that improve thermal management of a fuel processor by reducing heat loss and increasing burner efficiency.