NOVELTY - An electrochemical cell (72) comprises a membrane electrode assembly (76) comprising a first active area and an opposingly positioned second active area, each of active areas comprising electrodes and having a length to width ratio, such that a temperature differential measured across the shortest distance from a center of each of the active areas to an edge of the active areas is less than 15degreesC; and a flow field support having a flow region.    USE - The invention is used as electrolysis cell or fuel cell. It is useful as an anode feed electrolysis cells, cathode feed electrolysis cells, and regenerative fuel cells.    ADVANTAGE - The invention provides superior functionality. The shape of the flow field facilitates the dissipation of heat from the edges of the flow field supports, and radiation of the heat outward from the cell. Convective airflow along the edges of the flow field supports further enhances the efficiency of the heat removal. By effectively removing the heat, the life of the cell can be prolonged beyond the life of a conventional cell. The design allows for the removal of latent via the water stream from the cathode. Heat removal via a combination of the water stream and airflow enables the electrochemical cell to be operated with fewer plates (82). Because the cell stack (70) includes the stacked plates maintained in alignment by side plates, misalignment of the membrane electrode assemblies with respect to the plates is minimized. Because of the dimensions of the plates, a cell stack can be constructed from fewer plates than a fuel cell having the same output and power requirements, which translates into fewer pieces for assembly and service. Compression of the plates is also improved, in that multiple compression devices (74) exerting pressure against a common component tend to provide more uniform compression, over a greater area than conventional compression devices for cell stacks. By minimizing the angle at which the channels extend over the bipolar plates (78), a linear path for the flow of reactant gases and the removal of water is effected. Thus, minimizes the probability of fluid holdup in the channels, which also minimizes the amount of phase separation of the humidified reactant gases in the bipolar plates, further contributing to effective heat removal. The need for introducing a separate humidification stream is reduced, which, in turn reduces the amount of cell inputs. Use of the stream as a humidification stream reduces the by-product output of the cell, and promotes a more self-contained and self-sufficient aspect of fuel cell technology.    DETAILED DESCRIPTION - An electrochemical cell comprises a membrane electrode assembly comprising a first active area and an opposingly positioned second active area, each of the active areas comprising electrodes and having a length to width ratio, such that a temperature differential measured across the shortest distance from a center of each of the active areas to an edge of the active areas is less than 15degreesC; and a flow field support disposed adjacent to the membrane electrode assembly, and having a flow region that aligns with the first or second active area of the membrane electrode assembly. INDEPENDENT CLAIMS are also included for:    (a) a method of cooling an electrochemical cell, comprising radiating heat from a fin extending from an edge of a flow field support of the electrochemical cell; and flowing air along the fin to convectively remove heat from the flow field support;    (b) a method of humidifying or heating a reactant gas fed to an electrochemical cell, comprising atomizing a liquid product stream of the electrochemical cell; and spraying the atomized liquid product stream onto the reactant gas; and    (c) a method of heating an electrochemical cell, comprising passing an electric current through a resistive heating component disposed at a flow field support of the electrochemical cell.    DESCRIPTION OF DRAWING(S) - The figure is an exploded perspective view of a cell stack.    Cell stack (70)    Electrochemical cell (72)    Compression devices (74)    Membrane electrode assembly (76)    Bipolar plates (78)    Plates (82)    Side plate (122)    Tabs (126)    Holes (128)