A system and a method facilitate the extracorporeal inactivation of pathogens of blood products. The system includes an input peristaltic pump, at least one apheresis device, at least one plasma-treating system, and an output peristaltic pump. The input peristaltic pump, the apheresis device, the plasma-treating system, and the output peristaltic pump are in fluid communication with each other. The plasma-treating system includes at least one primary ultraviolet light (UVL) device, at least one heating device, and at least one cooling device. The input peristaltic pump facilitates the flow of blood from a patient through the system. The apheresis device facilitates separating of plasma from one or more blood cells. The plasma-treating system heats the plasma, inactivates pathogens within the plasma, and then cools the plasma. The output peristaltic pump facilitates the flow of blood from the system and back to the patient.