A plate for a heat exchanger between a first medium and a second medium, the plate being associated with a main plane of extension and a main longitudinal direction and including a first heat transfer surface, extending substantially in parallel to the main plane and arranged to be in contact with the first medium, generally flowing along the first surface in a first flow direction; and a second heat transfer surface, extending substantially in parallel to the main plane and arranged to be in contact with the second medium, generally flowing along the second surface in a second flow direction. The first surface includes protruding ridges defining at least two parallel and open-ended channels extending in the first flow direction. The second surface includes a plurality of protruding dimples arranged in the channels between neighbouring respective pairs of the ridges.