I recall hearing about a doctor doing research on the
effects of exposure to cold water. Perhaps this was
some naval (or other military) research? At any rate,
similar research had been done in WWII Germany, and
the data was, shall we say, more complete.
I believe the researcher was denied access to the data,
and undergraduates (and extrapolation) had to suffice.
My apologies for the sketchy data, but the above is
correct to the best of my memory.