"Cold water immersion experiment at Dachau concentration camp presided over by Professor Holzlohner (left) and Dr Rascher (right). The subject is wearing a Luftwaffe garment. Note the floating blocks of ice."

Taken from: Hanauske-Abel, Hartmut M. "Not a Slippery Slope or Sudden Subversion: German Medicine and National Socialism in 1933." BMJ: British Medical Journal 313(7070): 1453-1463. 7 December 1996.

No copyright status noted in the original article. The copyright holder was probably someone working at Dachau, and any copyright which was once held is probably lapsed. But without definite knowledge otherwise it is assumed to be copyrighted, and its use on Wikipedia is no doubt "fair use" for its historical purposes, the lack of an existing market, etc.