A mould tool comprising: a first layer having: a peripheral wall; a workpiece profile surface, the workpiece profile surface defining a workpiece profile; and, a temperature control surface opposite the workpiece profile, the temperature control surface at least partially bounding a plurality of fluid chambers within the peripheral wall, the fluid chambers each having an exhaust; a second layer having an exhaust port in fluid communication with the exhausts of the fluid chambers; a third layer adjacent the second layer; a support assembly, the third layer being mounted to the support assembly and, a plurality of first fluid-based temperature control assemblies mounted within the third layer, the first fluid-based temperature control assemblies configured to control the temperature of the mould tool by directing fluid into respective fluid chambers; and, characterised by: a peripheral chamber arranged outside the periphery of the workpiece profile and in conductive contact with the exterior surfaces of the peripheral wall of the first layer, which peripheral chamber is fed by the exhaust port of the second layer, wherein the peripheral chamber is configured to urge a fluid flow from the exhaust port in the direction of the workpiece profile surface to reduce heat loss from the peripheral wall. a first layer having: a peripheral wall; a workpiece profile surface, the workpiece profile surface defining a workpiece profile; and, a temperature control surface opposite the workpiece profile, the temperature control surface at least partially bounding a plurality of fluid chambers within the peripheral wall, the fluid chambers each having an exhaust; a peripheral wall; a workpiece profile surface, the workpiece profile surface defining a workpiece profile; and, a temperature control surface opposite the workpiece profile, the temperature control surface at least partially bounding a plurality of fluid chambers within the peripheral wall, the fluid chambers each having an exhaust; a second layer having an exhaust port in fluid communication with the exhausts of the fluid chambers; a third layer adjacent the second layer; a support assembly, the third layer being mounted to the support assembly and, a plurality of first fluid-based temperature control assemblies mounted within the third layer, the first fluid-based temperature control assemblies configured to control the temperature of the mould tool by directing fluid into respective fluid chambers; and, characterised by: a peripheral chamber arranged outside the periphery of the workpiece profile and in conductive contact with the exterior surfaces of the peripheral wall of the first layer, which peripheral chamber is fed by the exhaust port of the second layer, wherein the peripheral chamber is configured to urge a fluid flow from the exhaust port in the direction of the workpiece profile surface to reduce heat loss from the peripheral wall. a peripheral chamber arranged outside the periphery of the workpiece profile and in conductive contact with the exterior surfaces of the peripheral wall of the first layer, which peripheral chamber is fed by the exhaust port of the second layer, wherein the peripheral chamber is configured to urge a fluid flow from the exhaust port in the direction of the workpiece profile surface to reduce heat loss from the peripheral wall.