I’m considering buying a bivy to add warmth to and protect my Mountain Hardwear Phantom 32 sleeping bag, which I chose for its light weight. I cp mostly in lean-tos or other minimalist shelters ...

The Outdoor Research Aurora Bivy ($169; outdoorresearch.com) is a perfectly decent Gore-Tex bivy bag, in which you ll be reasonably snug and exceedingly uncomfortable because you can t sit up ...

One-person tent vs bivy sack: about bivy sacks Despite all the modern materials, bivy sacks remain a simple concept; basically a bivy is a waterproof, breathable bag to go over your sleeping bag.