A lithographic apparatus includes a substrate table constructed to hold a substrate, a projection system configured to project a patterned radiation beam through an opening and onto a target portion of the substrate, and a conduit having an outlet in the opening. The conduit is configured to deliver gas to the opening. The lithographic apparatus includes a temperature control apparatus disposed in a space between the projection system and the substrate table. The temperature control device is configured to control the temperature of the gas in the space after the gas passes through the opening.