Anyone selected for slave labor rather than immediate gassing was subject to processing. All hair was shaved off, to prevent the spread of lice. A number was tattooed onto the arm. This number became the official identity of the prisoner in the camp. All personal belongings were confiscated. The prisoners were stripped of their clothes, sent to showers for delousing, and given poorly-fitting uniforms and shoes. New arrivals were then sent to the barracks, where they had to sleep crowded together on wooden platforms.