I have to put in a word for silk long-johns and long-sleeve undershirts. On the recommendation of a friend who said it was her favorite item clothing on a year spent in England, my wife and I bought some for our honeymoon to Scotland. That stuff feels like it radiates heat the moment you put it on. Down has that effect, too; I have never experienced it with anything other than these two materials. I love microfleece and SmartWool but my silks are my favorite. They are are packed on any trip other than the hottest part of summer. Even after they are worn-out and starting to develop holes (silk wears out faster than synthetics) they go into the car as emergency gear. They have kept my cold-blooded self from being uncomfortable on many occasions.
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"After I had solaced my mind with the comfortable part of my condition, I
began to look round me, to see what kind of place I was in, and what was
next to be done"