Trying to get back to the original question.

In my opinion there are some serious differences when it comes to SAR emergency overnight stay, and Personal emergency overnight stay.

First, when you are packing for SAR you are not thinking of yourself. As you pack your SAR bag, you’re packing for not only yourself, but for the person or people that you are going to rescue. So you would want your Bivi to be able to accommodate not only you but also those that you are rescuing. So now you’re not carrying food for one, rather now you are carrying food for everyone. Suddenly the truth of the Burden of the rescue comes into play.

Secondly the key to successful overnight stays in the winter is seemingly simple, keep warm and dry. You can keep dry by keeping your body heat contained so that your outer layer is below freezing and your inner layer is warm enough for you to not get hypothermia. If you could manage that water proofing the outer layer isn't as critical, but the truth is that you will never get that situation. An outer waterproof and breathable layer is imperative. Keep in mind that your water vapors (aka sweat) is also not your friend.

A marginal lower body Bivi sack is a backpack that has a stuff styled closing (one of the ones that has a flip over top and a draw string closure on the top) this will allow you to hopefully put your lower body in the backpack and thus use the back padding as a form of insulation. While this works for some, I resort to carrying a Gortex Bivi sack and an emergency Bivi sack.


While I was doing SAR I carried a pallet bag, they ones that they put over pallets to keep them dry, in my backpack. The bag was about 6 mil plastic, and HUGE. I had fit about 4 people and myself into the bag. It was a great mulit-person Bivi sack. The down side was that it was plastic and thus could not wick away moisture and it would get condensation on it easley.


Granted if you are in an area that has greens still on the trees you can make a bedding and shelter. but if you are looking for materials and clothing for yourself I would go bivi-sack and I would ensure that warm layers were available in either the form of sleeping bags and blankets or warm clothing and socks.

Just my thoughts.