A process for the thermal deposition coating of a workpiece is provided that comprises the steps of: thermally depositing a coating on a metallic surface of a workpiece from a deposition head wherein at least one condition selected from the group of: coating deposition rate onto said surface, relative motion between the surface and said deposition head, and cryogenic coolant application rate onto said workpiece is controllable; substantially simultaneously measuring temperatures at a plurality of locations over the metallic surface of the workpiece; determining an average temperature of the temperatures measured in step (b); comparing the average temperature to a preselected minimum temperature and a preselected maximum temperature for the workpiece; and adjusting at least one of the controllable conditions if said average temperature is not between the preselected minimum temperature and the preselected maximum temperature for the workpiece.