>Are such adaptations genetic or environmental?  If the people in the crew
>lived there, and tried to dress like the native as much as possible, would
>they too develop this adaptation after some number of seasons?

Hard to say. I think there is a "general" physiological adaptation that takes place (as others have reported). But, does it mean the growing additional capilaries in the hands (extemities)? I don't know.

Personally, I seem to be naturally "pre"-adapted to the cold. I wear shorts and t-shirts late into the year while everyone else around me is bundled up. During the summar months I perspire far more than everyone else. Yet, every once in awhile I see the opposite - someone walking down the street in a coat during 80F+ weather. 

It's funny too, because as a child I was never able to handle cold weather very well. That's why as an adult I don't (downhill) ski.