(1) Yes, COLD vancomycin can definitely cause serious problems. Here is what I wrote in my complaint regarding a January 2017 cold vancomycin incident: "Our complaint regards the use of EXCEPTIONALLY COLD (STRAIGHT FROM REFRIGERATOR) liquid vancomycin (200 ml bag) in patient's IV line. Before the COLD vancomycin IV was administered, patient while sick was stable. Immediately thereafter, patient started SHAKING and SHIVERING (tremors). Within a very short time period patient went into a sort of SHOCK - his ordinarily good OXYGEN went to BELOW 60, his ordinarily good HEART RATE went to 150, and his ordinarily lower BLOOD PRESSURE went to 175/79 (since ER monitor does not show constantly the changing blood pressure we do not know if it went higher during this time). According to our limited research on the internet, it is NOT recommended to give COLD IV fluids because they can cause many different serious medical problems, all the more so in elderly people who often are immune-compromised. See attached, for example, two short questions and answers that we copied: https://allnurses.com/nursing-patient-medications/cold-iv-fluid-476214.html Why are cold iv fluids bad " Except in circumstances that require it, there is not any reason to give COLD intravenous drugs. Many hospitals have specialized warmers for these fluid bags, and those hospitals that do not just leave the bags out to warm up. (2) Yes, a FAST Infusion Rate (133 ml/hour) can definitely cause serious problems. Regarding a recent incident in January 2018, patient went into serious distress and quickly started turning dark purple on both of his arms. We required the doctors to decrease the infusion rate (they wanted to take their time to decide and talk it over among themselves, and we knew that time was not on the patient's side), and it was decreased to 75 ml/hour. IMMEDIATELY after the infusion rate was decreased, patient settled down and became calm. Thereafter, we required the attending doctor to write up the vancomycin as a "CONDITIONAL allergy", with a note that if vancomycin is to be given it must be given at NOT MORE THAN 75 ml/ hour. I really did not have time to write this email, but after seeing all of your responses I felt that it was my duty to write to all of you. PLEASE be careful regarding these two issues (COLDNESS of vancomycin and FAST infusion rate) since it is so easy to take necessary precautions and thereby not put patients at potential risk since you do not ever know which patients can tolerate coldness and fast infusion and which patients cannot.