A substrate handling system includes: a thermal shield for thermally insulating a space through which a substrate passes, from a thermal load originating outside the space, the thermal shield including: a first wall and a second wall with a gap therebetween, the first wall positioned between the space and the second wall; an inlet opening configured to allow a flow of gas from a gas source to enter the gap from outside the space; and an outlet opening configured to allow the flow of gas to exit the gap to outside of the space, wherein the system is configured to direct the flow of gas to enter the gap through the inlet opening, to flow through the gap and out of the gap to outside the space through the outlet opening thereby to reduce thermal fluctuations in the space due to the thermal load originating outside the space.