Abstract: A coolant delivery device (100) comprises a coolant outlet (124) and an exhaust (140, 160). The coolant outlet (124) is contained within a housing (150) that has an opening provided with sealing means (180), to which opening the coolant outlet (124) is arranged to direct a coolant. In use of the device, coolant is delivered to a surface to be cooled, and the coolant vaporises at the surface so as to produce coolant gas. Since the sealing means (180), in use of the device, form a seal between the housing (150) and the surface, the coolant gas is constrained to escape the device through the exhaust (140, 160), and does not disturb or disrupt the ambient environment. The device is particularly useful for applying thermal tensioning to welds through the delivery of a cryogenic spray to a weld line.