 Preventing hypothermia during surgery helps block infection. If a patient's body gets cold, it has a harder time fighting off germs. Patients are often kept warm using forced-air warming systems, but there's been concern that these devices disturb airflow in the operating room, potentially increasing the chance of airborne contamination. To assess this risk, researchers in Japan studied if laminar flow air currents around an operating table are changed by forced-air warming. Sophisticated laminar airflow systems are used to keep ultra-clean air moving through the operating room and prevent outside air from getting in. This constant current reduces the presence of airborne germs, thereby reducing the risk of infection. Disrupting this flow potentially allows stagnant air to accumulate around a patient, upping their infection risk. To determine how forced-air warming changes the airflow in the operating room, a mannequin was placed on an operating table and covered with a surgical drape. Either an upper body or lower body warming blanket was placed on the mannequin to mimic different types of surgery. These blankets inflate like a balloon when the attached heating device is turned on. The team then assessed the airflow in the room with and without forced-air warming and in the presence and absence of laminar flow. Airspeed and direction were measured at 504 different points in the room. The results showed that the forced-air warming system created convective airflow, causing air to recirculate around the mannequin instead of simply passing over it. But restoring laminar flow counteracted this effect. The group also filled the room with smoke and used lasers to visualize air movement under different air flows. Then, in the absence of laminar flow, the forced-air warming system caused air to recirculate over the mannequin's body. The stagnant air was cleared out, however, when the laminar flow was re-established. Although some elements of a working operating room that could have impacted airflow were missing, there was no healthcare team present, for example, and the overhead surgical lights were not positioned as they would be for an operation, these results suggest that forced-air warming systems are safe for keeping patients warm during surgery.