Abstract: A dual-fluid heat-exchanging system (20) incorporating a primary heat exchanger (22) and a secondary heat exchanger (24) is provided. The primary heat exchanger (22) incorporates a core (40) configured to extract heat (32) from a primary fluid (34). An input tank (30) and an output tank (28) are coupled to the primary-exchanger core (40) and function as reservoirs of the primary fluid (34) and as manifolds routing the primary fluid (34) through the core (40). The secondary heat exchanger (24) incorporates an extruded metal core (26) coupled to the primary-exchanger input tank (30) or the primary-exchanger output tank (28) and configured to transfer heat (32) from a secondary fluid (52) into the primary fluid (34) within the primary-exchanger input tank (30) or output tank (28). An input manifold (62) and an output manifold (64) are coupled to the secondary-exchanger core (26) and route the secondary fluid (52) through the core (26).