Take one or two clean athletic (no heel) sock(S), to each sock add 2 to 3 cups grain. Rice is very good, popcorn is a bad idea, won't work, but buckwheat, wheat, quinoa will all work. Tie a simple knot in the top of the sock. Place in a microwave up to 2 minutes per sock. Shake up and see if more warmth is required. Place along cold limb. Warm, oft, reusable, no pressure sores heat that lasts for several hours if you and the "hot sock" are covered up. We keep about four of these socks handy when traveling. They warm the cold pot, warm the bed, feel good a foot flop supports, keep containers o liquid from falling over for straw drinking. Quite handy, and if you loose one, not a large investment.

yes, warm/hot water is the only way in my experience to warm up those night 'icicle' limbs, that truly DO prevent me from sleeping for hours! hot water bottles and other warming devices are second best. direct contact with water works best because water is such a great conductor of heat (and cold if cooling is needed). i do have to be careful if my legs are particularly cold, not to warm up with hot water right away, but to take a few minutes and gradually increase the temp. tissues can be damaged if the contrast of hot water and cold skin is too great, too quickly. (like a frost bitten nose can't be taken into heat too quickly or skin will die--not quite the case for cold limbs, but the PRINCIPLE is essentially the same for low circulation areas). circulation and keeping heat seem to depend on the number of active, alive nerves one has in one's limbs. so more types of spasticity or voluntary movements per limb=better circulation and heat movement from the warmer parts of the body.

If there is one thing I hate more than being cold, I can't think of it. That's why I moved from NH to Tucson AZ. When it gets below 80 degrees I'm cold.