I just hate getting into a sleeping bag that has been sitting at -10 Deg F for the whole day. It is nice to use a Hand Warmer or the MRE Chemical Heater - if you have them. Rocks seemed like something I should try.

I made the normal RING OF ROCKS for the campfire. Several softball sized were placed to ring the fire. Larger rocks on the outside contained the heat.

When the time came, I wrapped the SOFTBALLS in paper towels. I don't like dirt and soot. These I stuffed into small oven bags - turkey bags. Both have an upper temperature limit of ~400F. I stuffed them into the sleeping bag and rolled it up.

That works!

The next test is to use the rocks thru the night for someone who can't stay warm.

When I went trekking in Nepal, I was always given a bottle full of just-boiled water to take into my sleeping bag at night. It really helped with staying warm, and provided safe drinking water for when you woke up.

I don't see why a hot stone wouldn't have the same warming effect, but it probably would not be as thirst quenching!

Anyone know at what temperature the synthetic liners of sleeping bags start to melt?

During winter camping and hiking, a bottle full of hot water is better then heated rocks. We usually will put the hot bottle into a couple of spare socks then into the sleeping bag. These stay warm for many hours and in the morning, you have water that is not frozen and is ready for use.

Thanks for the idea, ponder! i'm going to try that the next time i get a chance!

Per wikipedia, nylon 6.6 melts at nearly 500F. As long as your turkey bag is intact, your bag should be OK.

The rocks provide heat, but also compress the insulation.

I prefer to wear a wicking layer to bed. It helps keep me warm and protects the bag from my grunge.

Or, you can do it the easy way: Hot Water Bottle

Sue

+1. I do this head to toe, including some nice, dry wool socks (or camp booties, even better). The result is an instant toaster effect when I crawl into my sleeping bag. Plus, I have a layer of armour against the 4 a.m. cold should I need to take a short, uh, stroll.

I guess I would try the rock thing on a survival exercise. Probably on the foot end. Seems like a lot of fuss though.

My problem with heating rocks is how to handle them effectively when heated. I've heated both rocks and bricks, and find them extremely awkward to move around. Burns aren't going to increase your comfort or survival rate.

If anyone has any tried-and-true tips on how to maneuver them, please post! It can't be just me!

Sue

Tie two sticks together with a piece of cord and use them like a nutcracker.

The preferred method (when available) is rub two 'campers' together in a double bag. :-) Warms the bag rapidly and the afterglow morphs blissfully into sleep......
Extensive practice is not necessary, but hones the techniques....

lc