Run fuel cell coolant through cathode intercooler

A fuel cell system 10 comprises a cathode 14 and anode 16, a cathode air feed 20 and anode gas feed 24, a cathode air feed compressor 28, and a heat exchanger 30 loop configured to extract heat from the compressed cathode air feed. The heat exchanger loop is configured to circulate a heat exchanger fluid from the compressed cathode air feed to the fuel cell to pre-heat the fuel cell during fuel cell start-up. Also disclosed is a method for pre-heating a fuel cell during start-up using this fuel cell system. The heat exchanger loop may also be used to pre-heat the anode gas and cathode air feeds, and may be configured to heat or cool the respective feeds to minimize thermal differences and stresses in the fuel cell. This arrangement is especially useful for high temperature (HT-PEM) hydrogen fuel cells, such as those used in fuel cell powered vehicles, particularly fuel cell powered aircraft.