Not sure we should be doing it, but after much urging of our anesthesiologists, we have started doing cold screens again on patients scheduled for heart surgery. We do tube screening at room temperature and at 4 degrees and incubate for 30 minutes. If that screen is positive, we then do a more complete study. We test patient's plasma at 4 degrees, 12 degrees, Room temp, 30 degrees and 37 degrees, with an incubation of 60 minutes. We report out the strength of reaction seen at the different temperatures. Apparently, they have used the information to adjust the core temperature they take the patient to with better outcomes. Lou Porter, MBA, MT(ASCP), SBB