Treatment of Soviet POWs was unusually harsh. In the beginning, it seemed not to have differed much from the treatment that Polish or French POWs received. As one Curt Emmrich, a frontline surgeon in the German Army Medical Service and who wrote a book under the name of Peter Bamm, recalled in a book of his, this changed rather quickly with the unexpected fast gains of the Wehrmacht and the surrendering of hunderds of thousands of Soviet forces.[1]

We know from other German accounts of the catastrophic conditions in the transit camps (dulags): "The dulags faced a near impossible task under the chaotic conditions of the fall and winter of 1941/42. The rapid initial advance produced so many prosiners that the collections camps were simply overwhelmed. When 20,000 POWs crowded into a facility designed for one-tenth as many, disorder and hunder were the result."[2]

The situation of the Soviet POWs improved somewhat - though from a rather low point - after spring 1942: The camp system was stabilized, food provisioning and shelter imporved. In fact, once the German government realized that the war would be drawn out and the POWs labour could be used, they semed to show an interest in keeping Soviet POWs in better health. Nevertheless, the death rate among Soviet POWs remained extraordinarily high, particularly when compared to the fate of Allied POWs. The accepted figure is that between 55% and 58% of roughly 5 million Soviet POWs died in captivity.[3]

Sources:

[1] Peter Bamm: The Invisible Flag. London: Faber & Faber, 1956

[2] Konrad H. Jarausch: Reluctant Accomplice: A Wehrmacht Soldier's Letters from the Eastern Front. Princeton: Princeton University Press, 2011

[3] Evan Mawdsley: Thunder in the East: The Nazi-Soviet War 1941-1945. London: Bloomsbury Publishing, 2005 - ISBN 9781472511669