Fuel cells for example solid oxide fuel cells require cooling to maintain temperature levels and remove thermal energy generated by the fuel cells. The present invention provides a fuel cell assembly comprising at least one fuel cell. The fuel cell comprises an anode, a cathode, an electrolyte interposed therebetween, an interconnect which is in intimate contact with at least one of the anode, the cathode and the electrolyte; at least one fluid flow channel which is disposed within the fuel cell, and at least one fiber which is disposed within the fluid flow channel. The fiber disposed within the fluid flow channel disrupts a fluid flow during travel of the fluid within the fluid flow channel to generate unsteady wakes. These unsteady wakes enhance the local heat transfer characteristics adjacent to at least one fiber. A higher Reynolds number enhances the heat transfer characteristics proportionately. Enhanced heat transfer characteristics increase the ability to remove heat more efficiently and more effectively.