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 (T des ) 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 (Q PBP , Q REP1 , Q REP2 ) of an infusion fluid in the at least one infusion line (15, 21, 25)； calculating a set point value of an operating parameter (T OUT ； P w ) 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 (T des ) 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 (T des ) and at least one selected in the group of: the first signal (Q REP1 , Q PBP , Q RFP2 ) and a second value representative of a temperature (T REP1 , T PBP , T REP2 ) of the at least one infusion fluid in the at least one infusion line (15, 21, 25).
