Abstract: Apparatus, method and wellbore installation to mitigate heat damage to well components during high temperature fluid injection operations such as steam injection from surface through a wellbore. The apparatus includes an injection tubing that conveys the high temperature fluid to an injection zone and an isolation packer through which a lower end of the injection tubing passes. A pipe extends alongside the injection tubing with an outlet end close above the packer. When the apparatus is installed in a wellbore, the pipe creates a cooling fluid circuit that flows from just above the packer up in the wellbore alongside the outer surface of the injection tubing to surface and then back into the pipe.