A nonlinear coolant tube adapted for use in a heat exchanger core that is configured to port a hot fluid therethrough and a cold fluid therethrough while maintaining isolation of the hot fluid from the cold fluid, and including a hot circuit defining a hot circuit inlet, a hot circuit outlet, a first edge, and a second edge, the first edge distal the second edge, the first edge proximate the hot circuit inlet and the second edge proximate the hot circuit outlet. The nonlinear coolant tube is configured to provide a non-uniform heat transfer profile between the hot fluid and the cold fluid from the first edge to the second edge, such that a thermal resistance of the nonlinear coolant tube near the first edge is greater than the thermal resistance of the nonlinear coolant tube near the second edge.