Air is the main carrier of heat, moisture, and other contaminants including the airborne pathogens in the hospital operating rooms. Airflow patterns within the operating rooms and especially in the sterile zone determine the levels of air speeds, temperature, and contaminant concentrations. The spread of pathogens from the sterile zone is directly related to the airflow patterns in the room. This paper with the help of computational fluid dynamics (CFD) analysis demonstrates the effect of return locations and strength of heat sources on the resulting airflow pattern, temperature distribution, and thermal comfort of the occupants within the operating room.