Doc eats his quick breakfast, does his business, and then gets himself harnessed to the wagon/sled thing. 'A Wagon pulling a wagon'. Heh heh, mind readers would be groaning all day at the bad jokes he came up with, though this one was a bit old.
He does a little stretching exercise to warm up. "If at all possible, try not to ask us to stop suddenly. On snow this contraption is gonna have all the grace and control of a pregnant Brahmin on skates."