Method for cooling a fuel cell assembly

The method comprises discharging a heat of a fuel cell assembly using coolant such as a deionized water, and adding a nonionic surfactant to the coolant. The surfactant has a cloud point of below 20[deg] C, and is a low-foam surfactant. A concentration of the surfactant dissolved in the coolant is less than 0.1 vol.%. The fuel cell assembly comprises membrane-electrode assemblies (3) arranged between bipolar plates. An independent claim is included for a fuel cell assembly.