Delmera Tear-Resistant Reusable Bivy

Originally developed as a one-person shelter to protect mountaineers and climbers from rain and snow during multi-day ascents, the bivouac sack — or bivy sack — now has a wider range of uses. A traditional bivy sack, made from a waterproof, tear-resistant fabric, performs two basic functions: to increase the user’s body temperate and keep them dry.

Bivies — reminiscent of an ultra-lightweight sleeping bag or extra-large rain jacket shell — have all have a built-in head opening and come with features like drawstrings around the head opening to seal out moisture, full-length zippers and factory-sealed seams for extra warmth. The outer shell of the sacks is available in many different colors, including bright, attention-grabbing hues like red and yellow to improve the user’s visibility to rescue crews.

The products, which are stored in a compact bag, are ideal for emergency preparedness, backcountry excursions, long-distance biking trips, train running and winter camping. The primitive shelters are ideal for sleeping in technical terrain, where ledges are too cramped for a tent, but can also be used as a poncho, blanket, sleeping bag liner, ground cover and more. Some bivy sacks are also equipped with a whistle and a nylon core drawstring that can be used to secure or repair gear, making those options great for emergency situations. Because bivies can be reused, easily stored and often weigh just a few ounces, they’re convenient for travel and outdoor adventure.

What’s the difference between a bivy sack and a bivy shelter? The latter is a low-rise tent that includes mesh panels attached to the head opening or hoops to keep the fabric off your face (think: a fancy bivy sack).

• Depending on the product, bivy sacks are designed to help users retain up to 90% of their body heat.
• If you’re a tent camper who wants to downsize to a no-fuss shelter, a bivy sack could be the answer; since they require no setup, pitching or breakdown, they’re great for adventurers who want to maximize their time with a fast overnight.
• Bivies are great alternatives to tents in warmer temperatures (for example, above 50).
• If you plan to use your bivy sack for camping, increase your comfort by placing a bottle filled with hot water in the core zone (your crotch or armpit area) for extra warmth, use a sleeping pad underneath for extra cushion and pull the drawstring around the opening snugly around your head to avoid breathing into the bivy and to seal out moisture.