I thought this image of Barry Kidston might be of interest. I checked the patent and it's NOT -30°C but 30°C. Just cool, not especially cold. The original patent work was by Albert Ziering who, at the time of the MPP+ was still alive and confirmed that he made it properly and suffered no ill effects. Later, MPP+ became an item of commerce without special precautions and at least 2 chemists who made it for commerce developed Parkinson's Disease.
MPP+ was tested as a treatment for Parkinson's disease in the 1950s and only with the death of 2 of the 6 patients stopped them going further.
My worry is that ALL new chemicals, especially recent patents, are a real danger. Look back before the 1970s - at least a)it was likely tested on primates & b)the work is pretty open, not using the oldest lie - statistics.
It's only my opinion, the main thing is the image.