The Germans made many experiments on humans, but as science, most of it was completely useless. There were no control groups, no scientific data keeping, no repeated tests and so on.

The only data that came from nazi experimentation on humans that were actually useful was that on hypothermia, or how the human body is cooled down until we freeze to death.

The nazis submerged people in ice-cold water and experimented on how quickly they lost body temperature. This way we know that keeping your neck and head dry and warm helps immensly if you are struggling against cold.

As far as I know, the documentation still exists, have been studied and mostly discarded as scientifically useless.