A heat exchanger includes a plurality of first members, and a plurality of second members located between adjacent first members of the plurality of first members. The plurality of first members each include a plurality of openings and a first flow path connected to the plurality of openings. The plurality of second members each include a second flow path connected to the openings of the adjacent first members. The plurality of openings and the first flow path of the first member, and the second flow path of the second member define a flow path for a first fluid. A region between the adjacent first members defines a flow path for a second fluid. The heat exchanger further includes a third member extending toward the region on the first member.