The disclosure relates to a method of gas cooling in fuel cells arranged in a stack. A hydrogen-containing fuel gas and an oxygen-containing gas react with one another in the cells from which a first waste gas and a second waste gas escape. The first waste gas contains less hydrogen than the fuel gas and the waste gas temperatures are higher than the gas temperatures at the inlet side of the stack. The proposed process involves cooling the oxygen-containing gas before it is introduced into a subsequent stack down to a temperature which for thermodynamic reasons is the preferred inlet temperature for that stack.
