Since the Nazis were fighting the Soviets in cold conditions, they did a lot of research on hypothermia. Their methodology involved putting Jews out in the cold and measuring how long it took for them to get hypothermia.

There was a lot of debate over whether the results of their research should be used or just be destroyed because using it might encourage future scientists to use immoral methods in their research. They ultimately decided to use that research.

But when they looked at the data, there was no real science happening. They were just freezing people to death out of cruelty with no benefit to science.

A lot of "Nazi science" is very overrated. Turns out cruel and hateful people don't make for good scientists. Science is done by people and people and if those people ignore morality, they become very warped. "Science at all costs, ignore morality" doesn't actually result in useful research. It may feel like ignoring ethics in favour of scientific progress is a strong pro-science stance, but it's just another fascist power fantasy.