I have one like this. Just bought a second one here :D Last year, when I was kayaking (not a particularly warm season), there was a situation where everything I had got completely soaked—including this blanket. I was in trouble, didn’t really have the energy for an all-night bonfire, drying, etc. I went to sleep in the tent in totally wet clothes, under this totally wet blanket. It heated up from the inside, and I fell asleep. In the morning, I was dry along with my clothes, and you could brush the water off the outside of the blanket with your hand :D This is just IT. No gimmicks, no membranes, synthetics or anything like that. In the rain, you are warm from the inside. There are two drawbacks: The size of the blanket is such that a “broad” person won’t be able to wrap themselves completely. Second, the blanket takes up quite a lot of space—folded, about as much as 2-3 laptops stacked one on top of another. 100% wool does the job :D ps. the musty smell fades quickly once you start using it, being surplus is not a problem.