Even with an ideal forecast and immaculate itinerary, adventures can go wrong. Nobody wants to plan for the unexpected overnight bivouac, much less pack for it. Enter the Helium Emergency Bivy: The ultralight emergency shelter system that you'll barely even notice is there. Using the completely waterproof and seam-taped protection of Pertex Shield+, this simple tube-like construction uses a cinch closure to seal out the elements and save on bulk. Weighing in at an undetectable 6 ounces and packing down to the size of a beer can, the Helium Emergency Bivy is the perfect piece to keep at the bottom of your pack for unpleasant surprises in the backcountry.