I think the "polarized hull" is only in the Star Trek Enterprise prequel which takes place prior to the founding of the federation and takes place where humanity had just achieved Warp 5 and has pathetic weaponry. Every single other Star Trek show (Original Series, The Next Generation, Voyager, Deep Space 9, and the later movies) use shields as in "shields up" or "raise shields". I believe the new Star Trek Discovery should also have shields.