Disclosed herein is an apparatus and method for annealing semiconductor substrates. In one example the method of annealing substrates in a processing chamber includes loading a plurality of substrates into an internal volume of the processing chamber. The method includes flowing a processing fluid through a gas conduit into the internal volume. The method further includes measuring a temperature of the gas conduit at one or more position utilizing one or more temperature sensors. The processing fluid in the gas conduit and the internal volume are maintained at a temperature above a condensation point of the processing fluid.