[pluma]

We're talking about nazi experiments. I'd assume that the "for Germans" part is implied.

"Caucasians" also seems the wrong abstraction here in either case. If you put a Swede or Brit and a Spaniard or Italian in the same room, they'll likely have different opinions the optimal temperature too, yet all of these are pointlessly grouped as "Caucasian" just because some people like to pretend it sounds less racist than simply saying "white" (which is an equally useless category for most concerns).