A fuel cell system that employs a procedure for delaying an air purge of a
fuel cell stack at system shut-down until the temperature of the stack is
reduced below a predetermined temperature. The fuel cell stack includes
an anode side, a cathode side, an anode input, a cathode input and an
anode exhaust. The system includes a temperature sensor for monitoring
the temperature of a cooling fluid flowing through the stack. The anode
side of the fuel cell stack is purged at the stack shut-down by directing
air from the cathode input line to the anode input line after the
temperature of the cooling fluid is reduced to a predetermined
temperature.