[bivouac sack for two]
When hypothermia threatens, sharing body heat can be the key to survival. This bivvy takes that conventional wisdom to its logical conclusion: a heat-trapping refuge for two. Tuck yourselves inside this 84 x 60-inch, seam-sealed bivvy, and the shiny lining on the inside reflects 90 percent of your body heat back to you, while the close proximity of the occupants boosts heat conduction.
The polyethylene material is thin and nonbreathable, and it doesn’t have any of the bells and whistles of traditional bivvy sacks, but it’s a lightweight, affordable, and packable (soda can-size) insurance policy. And it’s way better (quieter, more tear-resistant) than a cheap, foil-like space blanket. $23; 5.8 oz.; adventuremedicalkits.com