A system for controlling temperature of a patterning device in a lithographic apparatus is discussed. The system includes a patterning device support configured to support a patterning device and a reticle cooling system configured to provide substantially uniform temperature distribution across the patterning device. The reticle cooling system includes a first and second array of gas inlets configured to provide a first and second gas flow along a first and second direction across a surface of the patterning device, respectively, where first and second directions are opposite to each other. The reticle cooling system further includes a switching control system configured to control operation of the first and second arrays of gas inlets.