I'm guessing that thing weighs about 10-12 lbs and my pack is already 28 lbs.
Pretty sure it would get wet too, especially if it's snowing out. You open it up out in the boonies on an unscheduled winter camping trip and as it warms up the snow touching it melts, soaks through and you get wet.
That blanket is for treating shock and hypothermia victims, but I suppose you could use it in conjunction with a survival bivy.
RE: Hypothermia--if you're treating someone beyond the range of EMS, an easy and pretty effective way is to use strategically placed conventional hand warmers. Place one on either side of the neck, in each armpit, in each glove and boot (assuming they're dry or you have dry spares). You can also place them on either side of the groin if the person is cool with you digging around in their crotch.
Basically you put heat at the same pressure points you'd use for bleeding.
As for the survival side--My plan is to get out of the wind and/or snow as best I can--maybe put up a lean-to but probably make a treewell shelter, build a fire and change into the spare baselayer and socks I carry in my pack and try and dry the sweat out of my outer clothes by the fire. Stay dry as possible and warm.
