thermally agile is desirable zone control of tool temperature is also known in particular from the applicant 39 s earlier application published as wo 2011 048365 in this document heating and cooling means are independently associated with each tool u201c pixel u201d which may be defined as described below in one embodiment of wo 2011 048365 each heated cooled tool pixel has an independent in line heater cooler associated therewith comprising an internal channel in each tool pixel below the tool surface through which a heating cooling fluid is passed the pixels are arranged to tessellate to form the tool surface at their upper surface in wo 2013 021195 a first layer provides the mould tool face and is heated by impingement of an in line air heater a second layer sits beneath the first layer and provides exhaust channels for the used fluid a third layer sits beneath the second layer and holds the heater unit with the control electronics each in line air heater has a tube which extends from the heater in the third layer through the second exhaust layer to the first layer as such fluid is passed through the heater passed through the second layer in the sealed tube and is impinged on the back face of the first layer the used fluid then escapes downwardly through the second exhaust layer fig1 is a temperature profile of a known layered mould tool such as that disclosed in wo 2013 021195.