Sick prisoners could be admitted to infirmaries (sick bays). Many never returned: they were left to die or murdered. Prisoners who worked in infirmaries, like the French dentist Sima Vaisman (who had been deported to Auschwitz in January 1944), tried to aid fellow prisoners. But they were often helpless in the face of infernal conditions and chronic shortages of essential supplies.
The Revier [infirmary] is made up of a group of wooden barracks (ex-stables, as the inscriptions still on the doors indicate). […] No water, no plumbing. Light penetrates through little skylights in the ceiling. […] Black, dirty cots in three tiers. A repugnant straw mattress full of pus and blood with one or two blankets, and on each mattress at least two sick people, sometimes even three or four. […] And the sick, skeletal beings, almost all covered with scabies, boils, devoured by lice, all completely naked, shivering from cold under the disgusting covers. Their shaved heads strangely resemble each other. These figures of suffering, ageless, are all the same. I spend weeks trying to get accustomed to them, trying to distinguish one from the other.
Source: S. Vaisman, A Jewish Doctor in Auschwitz (Hoboken, 2005), pp. 35–6