Abstract: A heat exchanger has a plurality of rows of media guiding ducts (12) for passing a media flow, a plurality of rows of fluid ducts for passing fluid to be temperature-controlled, and strip-shaped flow profile parts (20). At a transition between guide parts of the flow profile parts (20) and their plug-in parts, two mutually opposite steps are formed. The steps allow the flow profile part (20) to sit on the adjacent end faces of a fluid duct without spacing. The flow profile part (20) does not project at any point into a free opening cross section, which is defined by the imaginary extension of the inner, mutually facing boundary walls of a media duct (12) and by a media inlet of this duct (12).

Abstract: A heat exchanger, at least comprising a plurality of rows of media guiding ducts (12) for passing a media flow and a plurality of rows of fluid ducts for passing fluid to be temperature-controlled, and having strip-shaped flow profile parts (20), wherein at a transition between the respective guide part of the flow profile parts (20) and their plug-in part two mutually opposite steps are formed, which allow the flow profile part (20) to sit on the adjacent end faces of a fluid duct without spacing, wherein the flow profile part (20) does not project at any point into a free opening cross section, which is defined by the imaginary extension of the inner, mutually facing boundary walls of a media duct (12) and by a media inlet of this duct (12).