The present invention relates to a device 20 designed to promote heat exchange to/from a medical liquid ML. The device comprises an inlet 21, an outlet 22 and a duct 23 adapted to contain a flow of the medical liquid ML.The duct is enclosed between two walls 230, 231, has a planar development defining a mean plane π, and comprises means 24 for promoting turbulence in the flow of the liquid ML. At least one wall 230 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 240, wherein each fin 240n 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 30 for use in a PD/APD treatment, comprising a polymeric structure defining a first part 31, suitable for pumping and distributing the medical liquid ML, SML, and a second part 32 comprising a device (20) similar to the one described above.
