Nazi human experimentation

• 1. Introduction

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  Nazi human experimentation stands as one of the most extensively documented atrocities of the Second World War. Between 1942 and 1945, physicians working under the authority of the Third Reich subjected prisoners in concentration camps across occupied Europe to procedures that left at least 15,754 documented victims, though the true number is believed to be higher. About a quarter of those documented victims died. Survivors, as a rule, did not walk away unharmed. Most carried severe, permanent injuries for the rest of their lives.

  The experiments were not random acts of cruelty. They were organized, recorded, and in some cases published in medical literature. At Auschwitz, a camp doctor named Eduard Wirths oversaw the selection and supervision of inmates for research purposes. At Mauthausen, a physician named Aribert Heim conducted comparable procedures. And at Dachau, an SS doctor named Sigmund Rascher reported his findings directly to Heinrich Himmler, the Reichsfuhrer-SS himself.

  After the war ended, Allied forces brought these physicians before a tribunal that became known as the Doctors' Trial. The testimony heard there, and the revulsion it provoked, drove two American Medical Association representatives to draft a document that would reshape the ethics of medicine worldwide: the Nuremberg Code.

  How did physicians trained to heal become instruments of systematic harm? What were they actually doing in those camps? And what do we do today with the data they left behind?

• 2. Cold, Altitude, and Pressure

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  In early 1942, prisoners at Dachau concentration camp were placed inside a low-pressure chamber designed to simulate altitudes of up to 68,000 feet. The purpose was to help German pilots survive emergency ejections at extreme height. Of the 200 subjects used by Sigmund Rascher in those high-altitude experiments, 80 died outright. The rest were murdered.

  Rascher documented one victim in particular in a letter dated the 5th of April 1942, addressed to Heinrich Himmler. He described a man of 37 years, noted as being in good health before the experiment began. Rascher timed the man's physical deterioration in detail: the subject began moving his head four minutes after being deprived of oxygen, suffered cramps a minute later, and fell unconscious shortly after. He breathed three times per minute until he stopped breathing entirely, 30 minutes after oxygen was cut off. An autopsy followed an hour later. Rumours circulated that Rascher also performed vivisections on the brains of subjects who initially survived.

  In a reply dated the 13th of April 1942, Himmler instructed Rascher to continue the experiments on prisoners already condemned to death. Himmler also asked that tests determine whether men who died could be revived. He stated that anyone condemned to death who was successfully resuscitated should be pardoned to life in a concentration camp.

  The freezing experiments followed a similar military logic. The German armed forces had been catastrophically unprepared for the cold of the Eastern Front, and Rascher was tasked with finding solutions. Beginning in August 1942 at Dachau, prisoners were forced to sit in tanks of freezing water for up to three hours. Others were stripped and left outside in below-freezing temperatures. In a letter from the 10th of September 1942, Rascher described dressing subjects in fighter pilot uniforms before submerging them. Some were fully submerged; others were immersed only up to the head.

  The Luftwaffe had already commissioned related research in 1941, producing between 360 and 400 individual experiments on 280 to 300 victims, meaning some subjects endured more than one session. After freezing, experimenters tested different methods for rewarming. One assistant later testified that some victims were thrown into boiling water. Himmler himself proposed a different method: forcing hypothermic victims into sexual contact with other prisoners. One documented case placed a hypothermic subject between two naked Romani women.

  Rascher presented his findings at a 1942 conference titled Medical Problems Arising from Sea and Winter. Soviet prisoners were disproportionately used in the freezing experiments, partly because the Nazi researchers wondered whether their genetics gave them superior resistance to cold.

• 3. Wounds and Disease

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  From about September 1942 to about December 1943, researchers at Ravensbruck concentration camp removed bones, muscles, and nerves from living prisoners without anesthesia. The experiments were conducted for the benefit of the German Armed Forces, studying how the body regenerates tissue and whether bone could be transplanted between individuals. Many victims were left permanently disfigured and disabled.

  On the 12th of August 1946, a survivor named Jadwiga Kaminska gave a formal deposition about what happened to her at Ravensbruck. She described being operated on twice, both times on the same leg. She said she was never told what the procedures involved. Each time she was left in extreme pain and developed a fever afterward, with minimal aftercare. Kaminska recounted being told the operations were performed simply because she was a young girl and a Polish patriot. For months after each procedure, her leg oozed pus.

  At Ravensbruck, sulfonamide experiments also ran from about July 1942 to about September 1943. Researchers inflicted wounds on prisoners, then deliberately infected those wounds with bacteria including Streptococcus, the organism linked to gas gangrene, and the bacterium responsible for tetanus. To make conditions resemble a battlefield injury, they cut off blood circulation by tying off blood vessels at both ends of the wound. They also forced wood shavings and ground glass into the wounds to worsen infection. The drug sulfonamide was then applied to test how well it worked.

  Malaria experiments at Dachau ran from about February 1942 to about April 1945 and involved more than 1,200 inmates. Prisoners had their hands and arms confined in cages filled with malaria mosquitoes until they contracted the disease, then received treatment with synthetic drugs at doses ranging from high to lethal. More than half died. In an affidavit submitted at the Doctors' Trial, Oswald Pohl described the Dachau malaria experiments as the largest of their kind, and said he had personally protested to Himmler because the physician Schilling continually requested more prisoners.

  At camps including Sachsenhausen and Natzweiler, viral hepatitis was tested from June 1943 until January 1945 by injecting subjects with the disease to find new inoculations. Most died. In mid-1942, in a small building behind a private home in Baranowicze in occupied Poland, a child estimated to be eleven or twelve years old was strapped to a chair beneath a mechanized hammer that struck him on the head every few seconds. The child was driven insane.

• 4. Mass Sterilization

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  From about March 1941 to about January 1945, experiments aimed at developing rapid, scalable methods of sterilization were carried out at Auschwitz, Ravensbruck, and other sites. The stated goal was a method capable of sterilizing millions of people with minimum time and effort. The primary targets were Jewish and Roma populations.

  Carl Clauberg was one of the most prominent physicians in this program. He began by X-raying women to confirm their ovaries were unobstructed, then administered injections of caustic substances directly into their uteruses, without anesthetics, over three to five sessions. Many women died. Others developed permanent injuries and infections. Clauberg recorded approximately 700 successful sterilizations. Women who resisted or were deemed unsuitable for further experiments were sent to the gas chambers.

  X-ray radiation became the favored method when injections proved unreliable. Women received abdominal X-rays for abnormally extended periods; men received radiation to their genitalia. After exposure, physicians surgically removed their reproductive organs, again without anesthesia, for laboratory analysis. Many victims suffered severe radiation burns. Some also received intravenous injections of solutions believed to contain iodine and silver nitrate. These produced side effects including vaginal bleeding, severe abdominal pain, and cervical cancer. Women who developed cancer were subjected to vivisection, with their cervixes and wombs removed.

  A separate and more ambiguous case involved a German anatomist named Hermann Stieve. William E. Seidelman, a professor at the University of Toronto, investigated Nazi medical experimentation in Austria in a report co-written with Howard Israel of Columbia University. Stieve used organs from executed criminals for research into the female reproductive system. Some sources claim he informed women condemned by the Gestapo of their execution dates in advance and monitored how psychological distress affected their menstruation. Allegations also circulated that some women were raped after being told their execution dates so Stieve could study sperm migration. These specific claims have been disputed; Seidelman himself noted they appeared to be incorrect, and no evidence exists that Stieve ever investigated sperm migration as a research topic.

  The sterilization experiments operated alongside a pre-existing Nazi policy. By the time camp experiments began, the German government had already carried out compulsory sterilization on 400,000 people.

• 5. Josef Mengele and the Twin Studies

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  In 1944, Josef Mengele arrived at Auschwitz with academic training in both genetics and anthropology. He had studied under Otmar von Verschuer, a scientist who had conducted comparative twin research on the general German population. Mengele brought that tradition into the camp.

  According to historian Paul Weindling, records show that 582 twins were gathered by Mengele for research. His precise motivations have been debated. Some have suggested he was trying to increase the German birthrate by studying how twins were produced. David G. Marwell, however, argued his interest was grounded in the established scientific practice of using twins to measure how much of a given trait is inherited. Mengele himself stated he was studying the formation of the human body.

  Twins in his program were spared forced labour, but they were subject to regular, lengthy physical examinations. Mengele employed educated prisoners who had training in anthropology to collect data. These prisoner-researchers used precision instruments to measure limbs and head circumferences, took dental impressions, and recorded details including eye colour and hair colour and texture. Blood was drawn regularly. One prisoner anthropologist later described the level of detail in Mengele's twin examinations as excessive, though she said she considered it more or less standard for anthropological work of the era.

  Witness accounts on deaths during the program are contradictory. Miklos Nyiszli, a prisoner physician, testified to performing autopsies on several twins killed by lethal injection. Another witness estimated 100 were killed for research. In contrast, the prisoner anthropologist who participated in examinations said she was not aware of Mengele killing any of the twins she measured, and the prisoner leader known as the twins' father said he had no knowledge of any killings. The figure of 200 survivors, often cited, derives from a Soviet headcount at liberation and excludes older twins who were sent on marches to other camps beforehand. Weindling has noted this has produced an exaggerated estimate of scientifically motivated killing.

  In October 1944, Mengele intervened to stop an order from a rival SS doctor named Heinz Thilo, who had selected as many as half of the twins for death. Mengele fled Auschwitz in December 1944. He gave no instruction for the twins to be killed before leaving, and no clear explanation for that decision was ever recorded. Historian Marwell has also urged caution about widely repeated allegations, including the claim that Mengele surgically joined twins to create conjoined pairs. Weindling has noted that several such procedures have been misattributed to Mengele and were actually performed by other doctors.

• 6. The Doctors' Trial and the Nuremberg Code

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  On the 19th of August 1947, Allied forces put 23 doctors and administrators on trial in a case formally titled USA vs. Karl Brandt et al. It became known as the Doctors' Trial.

  Several of the defendants argued that no international law governed medical experimentation on human subjects, and that military necessity had justified their work. Some compared their victims to collateral damage from Allied bombing campaigns.

  The question of informed consent was not entirely new to German medicine. In 1900, the physician Albert Neisser had infected patients, primarily prostitutes, with syphilis without obtaining their agreement. Most of the academic community supported Neisser. The psychiatrist Albert Moll led a public opposition and developed a legal framework grounding the doctor-patient relationship in contract theory. That framework was not adopted into German law. Eventually the minister responsible for medical affairs issued a directive stating that interventions outside of diagnosis, healing, and immunization required the unambiguous consent of a competent adult subject, but the directive carried no legal force.

  At the Doctors' Trial, the American Medical Association sent two representatives: Leo Alexander and Andrew Conway Ivy. Together they drafted a ten-point memorandum called Permissible Medical Experiment, which was adopted as the Nuremberg Code. The code required voluntary consent, the absence of unnecessary pain and suffering, and a reasonable belief that the experiment would not result in death or permanent disability.

  Despite its moral weight, the Nuremberg Code was not cited in the actual findings against any of the defendants. It was never incorporated into either German or American medical law. Andrew Conway Ivy himself stated the Nazi experiments had produced no medical value. That conclusion, however, has remained contested.

• 7. The Contested Data

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  Arnold S. Relman edited The New England Journal of Medicine from 1977 until 1991. During that time, he refused to publish any article that cited Nazi experimental data.

  The most debated set of findings came from the Dachau freezing experiments. By 1984, at least 45 publications had referenced that research in the context of hypothermia treatment, though the majority of publications in the field did not cite it. Robert Pozos of the University of Minnesota and John Hayward of the University of Victoria both argued in favor of drawing on the results. In a 1990 review, Robert Berger took the opposite view, concluding that the Dachau study contained all the ingredients of a scientific fraud and that the data could not advance science or save human lives.

  In 1989, the United States Environmental Protection Agency considered using Nazi research on the effects of phosgene gas, believing the data could help American soldiers then stationed in the Persian Gulf. The agency ultimately rejected the data, citing anticipated criticism and the availability of comparable animal studies. Writing in Jewish Law, Baruch Cohen called the EPA's refusal typical but unprofessional, arguing that using the data could have saved lives.

  The ethical divide runs along two distinct lines. Some oppose the use of the research purely on moral grounds, objecting to any benefit being derived from methods that violated human dignity. Others object on scientific grounds, pointing to methodological inconsistencies in how the experiments were conducted and recorded. Those who support selective use argue that withholding data with practical value is itself an ethical failure.

  The broader catalogue of atrocity includes crimes documented in Heinrich Himmler's own correspondence. In one transcribed passage, Himmler described supplying concentration camp prisoners to medical researchers as a personal responsibility, referring to those prisoners as asocial individuals and criminals who deserved to die. That framing, and the bureaucratic structure that made it possible, is what the Nuremberg Code was written to prevent from happening again.