The present invention relates to a device designed to promote heat exchange to/from a medical liquid ML. The device comprises an inlet, an outlet and a duct adapted to contain a flow of the medical liquid ML. The duct is enclosed between two walls, has a planar development defining a mean plane π, and comprises means for promoting turbulence in the flow of the liquid ML. At least one wall of the duct is suitable to allow a heat exchange with the flow of the liquid ML. The means for promoting turbulence comprises a plurality of fins, wherein each fin has a lenticular cross section and defines its own mean plane τn substantially perpendicular to plane π. The invention also relates to a disposable cassette for use in a PD/APD treatment, comprising a polymeric structure defining a first part, suitable for pumping and distributing the medical liquid ML, SML, and a second part comprising a device similar to the one described above.
