What Happens During Apheresis An apheresis nurse will take your temperature, blood pressure, and heart rate throughout the treatment and may draw blood, if lab work was ordered. A registered nurse will monitor the apheresis machine during your treatment. You will not be able to use the bathroom during treatment. You can request a bedpan or urinal, if necessary. Be sure to tell the apheresis nurse if you are experiencing chills, pain, tingling of the lips or fingertips, or other discomfort.