A heat exchanger (HEX) for cooling air in a gas turbine engine is provided. The HEX may comprise an intake manifold in fluid communication with a compressor section and configured to receive air from the compressor section, an outtake manifold in fluid communication with the intake manifold via a tube, and a cooling air flow path defined by at least one of an outer surface of the tube, an outer surface of the intake manifold, and an outer surface of the outtake manifold, wherein the cooling air flow path is orthogonal to said tube. The air from the intake manifold may travel through the tube to the outtake manifold and from the outtake manifold to a portion of the gas turbine engine.