In the winter, I wear socks to bed. Even so, some nights my feet are so darn cold I just can't sleep. Last night was one of them. After a long while spent shivering, I had to admit that I just wasn't going to fall asleep. I talked myself out of bed, and went to retrieve one of the hot/cold packs I made last Spring. Four minutes on high in the microwave, and my bag of flax seeds was nice 'n roasty toasty. It wasn't just my feet that were cold when I got back under the covers, but spending a few minutes hugging my comfort pack raised my body temperature to a more reasonable level. I moved the pack down to my feet and -- Ah! Warmth! With much happier feet, I finally fell asleep and stayed that way until morning.
I think I'm going to have to add heating the bag to my nightly routine.
Oh, and if you want to see what I'm talking about, or make one for yourself, the instructions are here on CrochetMe.com.