An extracorporeal blood treatment apparatus comprises: a blood treatment device; an extracorporeal blood circuit comprising a blood withdrawal line and a blood return line coupled to the extracorporeal blood treatment device, wherein the blood return line presents a heating zone coupled or configured to be coupled to a blood warmer; a blood pump configured to be coupled to a pump section of the blood withdrawal line; at least a post-infusion line connected to the blood return line upstream of the heating zone; an air trapping device placed on the blood return line upstream of the heating zone.