An extracorporeal blood treatment apparatus (1) comprising a control unit (10) connectable to a blood warming device (200). The apparatus (1) comprises: an extracorporeal blood circuit (100) and at least one infusion line (15, 21, 25) connected to the extracorporeal blood circuit (100). A control unit (10) is configured to execute the following procedure: receiving a first value representative of a desired blood temperature (Tdes) at an end (70) of a blood return line (7) configured to be connected to a venous vascular access of a patient (P)； receiving at least a first signal relating to at least a flow rate (QPBP, QREP1, QREP2) of an infusion fluid in the at least one infusion line (15, 21, 25)； calculating a set point value of an operating parameter (TOUT； Pw) to be imposed on the warming device (200) configured to heat a blood heating zone (H) of the extracorporeal blood circuit (100) in order to maintain the desired blood temperature (Tdes) at the end (70) of the blood return line (7). The set point is calculated based on input parameters comprising: at least the first value representative of the desired blood temperature (Tdes) and at least one selected in the group of: the first signal (QREP1, QPBP, QREP2) and a second value representative of a temperature (TREP1, TPBP, TREP2) of the at least one infusion fluid in the at least one infusion line (15, 21, 25).
