While attempting to provide a high level of patient care for Jews, Christians, and Arabs, Shaare Zedek operated without electricity, indoor plumbing, central heating, or gas cooking stoves. Kerosene heaters were used to warm bathwater, and paraffin lamps were used in the operating room. It was difficult to retain staff due to the working conditions and to the exacting, temperamental nature of Dr. Wallach. Nevertheless, Schwester Selma worked 18-hour days, and expected her nurses and aides to display the same work ethic.