Sigmund Rascher (12 February 1909 – 26 April 1945) was a German SS doctor.
He conducted deadly experiments on humans about high altitude, freezing and blood coagulation under the patronage of SS leader Heinrich Himmler, to whom his wife Karoline "Nini" Diehl had direct connections.
When police investigations uncovered that the couple defrauded the public with their supernatural fertility by 'hiring' and kidnapping babies, she and Rascher were arrested in April 1944.
He was accused of financial irregularities, murder of his former lab assistant, and scientific fraud, and brought to Buchenwald and Dachau before being executed.
After his death, the Nuremberg Trials judged his experiments as inhumane and criminal.