Abstract: The freeze-protected heat exchanger comprises a fluid supply header for receiving a pressurized heated fluid and a drain chamber coextending with the fluid supply header for collecting and draining cooled fluid. A plurality of heat exchanger tubes extends radially from the fluid supply header and drain chamber, and each comprise outer and inner pipes. The outer pipe has a heat-conductive wall, a proximal end in fluid communication with the drain chamber and a distal closed end. The inner pipe is disposed coaxially within the outer pipe, has a proximal end in fluid communication with the fluid supply header and comprises a plurality of first orifices through which the inner pipe is in fluid communication with the outer pipe. At least one second orifice through which the drain chamber is in fluid communication with the fluid supply header opens in the drain chamber.