NOVELTY - Fuel cell comprises a pair of collector plates having channels for flow of reactants, first and second gas diffusion layers between the collector plates, and a membrane-electrode assembly (MEA) interposed between the gas diffusion layers. A seal prevents transfer of reactance gases around the MEA.    USE - Freeze-tolerant fuel cell, preferably a proton exchange membrane (PEM) fuel cell with a water-permeable ion-exchange membrane.    ADVANTAGE - Reliable fuel cell operation at temperatures well below the freezing temperature of water.    DETAILED DESCRIPTION - Coolant passage(s) is (are) provided for flowing a coolant stream relative to the collector plates to cool the fuel cell, where the coolant stream does not contact the MEA.    The collector plates preferably provide separate coolant ports for transfer of coolant apart from the reactant flows and further comprises a pair of gaskets surrounding the coolant ports and disposed between the collector plates.    Preferably, a pair of sub-gaskets are provided. Each sub-gasket is positioned between the gaskets and extends into a position between the gas diffusion layers and the MEA, whereby the membrane is supported.    INDEPENDENT CLAIMS are given for:    (a) a method of using a fuel cell system in environments subject to sub-freezing temperatures;    (b) a method of shutting down a fuel cell system in environments subject to sub-freezing temperatures; and    (c) a method of starting up aq fuel cell system in environments subject to sub-freezing temperatures;    (d) a method of using a gasketed proton exchange membrane (PEM) fuel cell stack in environments in sub-freezing environments; and    (e) a fuel cell stack comprising at least one gasketed fuel cell.    DESCRIPTION OF DRAWING(S) - The drawing shows a freeze tolerant fuel cell system schematic comprising a fuel cell stack interfaced with a fuel processor and external cooling and humidification systems according to the invention.    Fuel cell stack (10)    Fuel processor (60)    Anode inlet (62)    Process water tank (64)    Anode separator (68)    Cathode (70)