The invention provides solid oxide fuel cell devices and a fuel cell system incorporating a plurality of the fuel devices, each device including an elongate substrate having a reaction zone for heating to an operating reaction temperature, and at least one cold zone that remains at a low temperature below the operating reaction temperature when the reaction zone is heated. An electrolyte is disposed between anodes and cathodes in the reaction zone, and the anode and cathode each have an electrical pathway extending to an exterior surface in a cold zone for electrical connection at low temperature. In one embodiment, the device is a multi-layer anode-cathode structure, and in another embodiment, the device is an electrode-supported device. The system further includes the devices positioned with their reaction zones in a hot zone chamber and their cold zones extending outside the hot zone chamber. A heat source is coupled to the hot zone chamber to heat the reaction zones to the operating reaction temperature, and fuel and air supplies are coupled to the substrates in the cold zones.