Twenty-seven-year-old SS-Hauptsturmführer Friedrich Charles Entress, a Nazi physician, begins working at Auschwitz I. He is an ethnic German of Polish descent. He is considered to be one of the most cruel Nazi doctors in the camp. He sends thousands of prisoners to death during selection, and sometimes, he executes the selected prisoners by injections himself and he performs experiments on them. He always keeps a straight face; he sends people to their death without mercy. Often, his decision is made only after a fleeting glance at the person.Medicine of the company of I. G. Farben, or of the Bayer Company, respectively, which was a subsidiary of this company, is tested on the prisoners. During at least one testing round of researching the treatment of typhus, healthy prisoners are intentionally infected so that Entress can observe how infectious the disease is.

Entress takes advantage of the opportunity to perfect his surgical skills, and so he operates on healthy prisoners. For him, they are merely biological material for experiments.


Since the spring, or no later than from the summer of 1942, experiments are done on the prisoners. Usually medicine from pharmaceutical companies is tested on them. Doctor Entress takes advantage of Block 28 in Auschwitz I, which soon gains the notorious reputation as being the male experimental block. At this phase of the research, Entress creates facilities for about two hundred patients. He tests typhus medicine for the Bayer company on the prisoners.

Entress also dabbles in a special treatment of tuberculosis, where an operation leads to the deflation of the affected lung. Prison doctor Dering assists during these operations, and the Nazi learns other surgical interventions from him, which they sometimes carry out together on healthy prisoners.

As for the tuberculosis, if a prisoner receives this diagnosis, they are immediately designated for liquidation by injections of phenol or in the gas chambers. Exceptions are only those that serve as subjects for research before their deaths.

Prison doctors often mask the diagnosis of tuberculosis with other diseases, and thus spare the patients from execution for at least several days more. However, in these horrible camp conditions, this disease usually leads to the demise of the patients anyway.


Simultaneously with Clauberg’s actions, Nazi physician Horst Schumann begins experimenting with the sterilisation of men and women in hospital Block 30 of the women’s camp in Auschwitz II – Birkenau. He, however, decides to use x-rays for this purpose.

He personally chooses youths and girls 18 to 20 years of age. They have to strip bare, and then stand in between two x-rays that radiate their genitalia for several minutes. Several of them die during the experiments after great suffering, and most of the survivors are sent to the gas chambers after the suffering ends, as they have radiation burns and are not able to work.

In order to discern the effects of the radiation on youths, Schumann tests their sperm. He uses a cane covered with a rubber hose, that is stuck into the anus of the victim, brutally massages the prostate and forces ejaculation. He sends the ejaculate to a laboratory in Breslau, today known as Wrocław.

Also, he has the testicles of selected youth removed and the ovaries of selected girls operated out. Sometimes, they are operated twice; in the first operation, one testicle or ovary is removed, and then, after some time, the victim loses possession of their other testicle or ovary. The obtained specimens are again sent to the laboratory in Breslau.


Ninety youths from a group of 180 young prisoners whose genitals were radiated in the previous days are castrated with only minimal anaesthetics, with only an injection into the spine. Those operated, paralysed by the injections, remain conscious and witness their mutilation. Their desperate cries resound in the surroundings of the operation room. Both, or just one, testicles are removed. The operations have an audience of SS officers, who are thoroughly entertained.

The castrations last all day into the night, and the surgeons are the prison surgeon Dering and the Nazi physician Entress. Due to the speed of the surgical interventions, some operations are shoddily done.

In the next days, the ovaries of the girls are removed, and again with the same speed and under the same amount of anaesthetics.

Unfortunately, some of the operated inmates must undergo another operation in the next few December days, in which they lose their other testicle or other ovary.

Several people die already during the experiments, and the entire episode ends for this group of youths and girls by their selection, and most of them are sent to the gas chambers. Some are sent back to work


5 May to 10 November

According to recordings and to the testimonies of prisoners, at least 130 young men are castrated by surgeon Dering in the period from May to December 1943. At the time, he is the prisoner assistant of Dr. Schumann. Most of the castrations are related to the experiments with sterilisation by x-ray radiation.


Dr. Schumann decides to do another experiment on the prisoners. He chooses twelve youths, and has surgeon Dering remove one or two of their testicles. The goal of the research is to observe how such mutilated young men change. After the war, David Szarbel, who loses his left testicle on this day yet eventually survives the suffering of the camp, provides testimony about these operations at the trial with Derin


Extensive experiments involving a mosquito begin on the prisoners in the experimental Block 28 in Auschwitz I, causing the death of many men. The Nazi doctors are testing new malaria medicine on them. If the prisoner is not infected after being bitten by the mosquito, they receive a transfusion of infected blood.

Experimental Block 28 remains closed to the common prisoners, and it is not exactly clear what sort of scientific research takes place there. Rumours talk of experiments with making prisoners hypothermic in the built-in reservoir, or of researching infectious hepatitis. Often, even healthy men are purposefully infected with it.

It is certain that there are experiments with various burns that emulate the burns caused by grenade explosions on the front. But there are also experiments meant to reveal cases of self-harm by German soldiers who want to get away from the front. They purposefully cause themselves various infections. The skin of prisoners is smeared with toxic substances, or they are injected under the skin. The men are affected by infected and dangerous wounds. There is no doubt that the prisoners selected for these experiments greatly suffer.

Block 28 has a photography studio, where pictures of the naked subjects of these experiments are taken. For some time, even Mengele has his twins driven there to be photographed.

Friedrich Entress
Friedrich Entress
Jerzy Potrzebowski
Jerzy Potrzebowski - Selection of prisoners
Jerzy Potrzebowski - Selection of prisoners