Well, we had a girls only camping trip last weekend. Since it was in the low 30s at night we had the whole camp site to ourselves. We saw wild pigs & wold turkeys & found fossils. It was awesome!!! Anyway, I got a chill before I got into my sleeping bag & my legs & feet just wouldn't warm up. I had one of those ThermaCare Heatwraps for my back so I opened one up & stuffed in the bottom of my sleeping bag. It was wonderful ! These things could really make a difference if you got into a really cold emergency situation. I am going to add a couple to my BOB. The other girls have all decided to add them to their camp supplies too.
Get the extra large, lower back size. They have a really big surface area so you get more bang for your buck. The package says they last 8 hours but mine always stay warm about 15 hours. The other nice thing is that they have a waist band & you can strap the thing on any part of your body. You can move it from place to place to warm you up. Costco has a 4 pack for about $11 . Here is a link so that you can see what they look like:
http://www.thermacare.com/lowerbackwraps.jsp
Get the extra large, lower back size. They have a really big surface area so you get more bang for your buck. The package says they last 8 hours but mine always stay warm about 15 hours. The other nice thing is that they have a waist band & you can strap the thing on any part of your body. You can move it from place to place to warm you up. Costco has a 4 pack for about $11 . Here is a link so that you can see what they look like:
http://www.thermacare.com/lowerbackwraps.jsp