The best grade of beaver pelts, ones that brought the best price, were heavy and thick with winter fur.  The French called them "plus" which translates into English as "plus" but is pronounced as "plews."  And that's what the trappers called them.   Modern day re-enactors use the word "plews", describing about any regular beaver pelt, but it was once reserved for only the finest.  In order to get hold of the finest plews, the trapper had to trap into the late, late fall.   They spent a lot of working days in snow and icy water.  They moved about some of the time by slogging through the white stuff.   Not easy for anyone but not as tough for them since they had a lot of experience over the years finding hidden trails and natural routes to get where they needed to be.  Did they feel the cold?

 Dang rights they did!