I'm not really a fan of this type of kit. The heatsheet although much tougher than a mylar sheet really does not provide any realistic protection against the elements. Same with the bivy made from the same material. Firstly, claims about reflecting 90 percent of the bodies radiant heat really is just marketing fantasy considering radiant heat losses are just a fraction of heat loss from convective heat. The Bivy bag is really just a metalized plastic bag with no real insulation qualities at all. It would be best described as a high tech body bag. Secondly this material is not breathable, which is always an important consideration in the survivability stakes. To keep warm you need to keep dry. To keep dry you need breathable materials. For an small increase in additional weight (an extra 400 gms) there are much more practical functional shelters available such as the Outdoor Research Lighthaven. The Lighthaven would allow 2 people to sit out a storm in relative comfort and allow the occupants to brew up a nice cup of hot sweet tea. A sort of more advanced version of the Bothy Bag.


Or there is also the Blizzard Survival Bag weighing in at 385 grams available at http://www.blizzardsurvival.com/