Emergency Blanket-bivvy

[stickat04]

When I do cold weather hiking I carry a emergency blanket I was thinking of switching to this product and was wondering if anyone has any feedback on it.

http://www.basegear.com/amk-heat-sheet-emergency-bivvy.html

[LostInSpace]

http://www.equipped.org/shot_show_2006_gear.htm

Edited: Sorry, this is not the same thing.

[Vi+]

I presume this is for an emergency situation, to hopefully never use.

I have seen the Heat Sheets Emergency Bivvy in stores, or something which looks like the photograph in the link you provided.

I haven’t used the bag you ask about, so I DON’T KNOW WHAT I’M TALKING ABOUT. I won’t let that "minor" impediment stand in my way.

The bivy sack I’ve seen in stores takes up a fair amount of space and, lifting it, it seemed heavier than the link-advertised 3.5 oz.

(I like the little hemispherical graphic with the range from 60% to 100% and the needle on 90%, as if percentages are to be confused with a thermometer's degree marks, implicitly suggesting you’ll feel warm.)

The Vapor Barrier Effect is the principle on which such bags work. The Vapor Barrier Effect can be gained with any impermeable barrier close to the skin; poncho, parka, garbage bags, even plastic wrap.

Weight isn’t a factor for the Vapor Barrier Effect. Additional weight only suggests a heavier bag will have greater resistence to punctures and tears. Duct tape, which is so versatile you may carry it already, will repair a lighter weight bag.

Windproof blankets and bags are obviously windbreakers, which can help a lot, but the Vapor Barrier Effect only elevates the ambient temperature about 22 degrees.

I use two Emergency Survival Bags which, combined, weigh 5.5 oz. Space Bags are probably lighter in weight. A blanket isn’t going to function as well as a bag, and I can always make a blanket by cutting the bag along one side and across the foot. One bag can be placed within the other, and the space between them filled with dry leaves and other detritus to form insulation; an emergency sleeping bag, which is a significant improvement over the Vapor Barrier Effect alone.

Alternatively, using a length of line or a well placed limb, an emergency bag can become a tube tent.

[peter_pan]

Probably better to use it as a vapor barrier inside a bag than over it as a condensation trap....

Pan