【Objective】 To study the safety, effectiveness and nursing of blood/fluid warmer during the process of plateletpheresis in winter. 【Methods】 The blood re-transfusion speed during plateletpheresis in winter and the time of blood passing through the blood return pipeline was counted. The vitro blood was heated with a blood/fluid warmer under different temperature settings, and the rising speed of blood temperature was recorded. The blood samples were tested for blood routine examination, free Hb and erythrocyte morphology at 0, 15 and 30 minutes. In the process of plateletpheresis in winter, the blood donors′ ear temperature and the skin temperature near the reinfusion needle in the observation group and the controls were measured, and the blood donors were observed for shivering, arm chills, pain or other discomfort. After the blood donation, the thermal comfort was evaluated. 【Results】 There was no difference in the results of routine blood test and plasma free Hb test of vitro blood after warming at 41℃, 42℃ and 43℃ for 0, 15 and 30 minutes (P>0.05), and no change in erythrocyte morphology was found. The skin temperature near the reinfusion needle (before vs. after the start of phlebotomy) was statistically different by applying blood/fluid warmer or not(P<0.05), and no difference in the temperature between the start and end of phlebotomy was observed in the observation group(P>0.05). The vitro blood heating experiment showed that when the room temperature was within 22~24℃, the blood retransfusion speed was (100-120) mL/min; after the application of blood/fluid warmer, the temperature of reinfusion blood could be raised from 27℃ to 33~37℃. The proportion of feeling comfortable and very comfortable and the score of thermal comfort in the blood donors who used the warmer were higher than those in the controls (P<0.05). When the temperature of the warmer was set above 38℃, the average score of thermal comfort of blood donors was above 8. 【Conclusion】 It is safe to apply the blood/fluid warmer during the plateletsapheresis in winter, which can significantly improve the comfort of blood donors and reflect the humanized service of blood stations, and is worth popularizing.