Sleeping with fire: Why sleep on the cold ground when you can warm it up a little.
Step 1. Excavate a section of soil around six inches deep and as long and as wide as your body.
Step 2. Gather all the hot coals from your fire and lay them in the bottom of your excavation.
Step 3. Fill in the hole and place your bed on top. The hot coals will heat up the soil and keep you toasty until morning. (Caution: If the coals aren't buried deep enough you will find out what a roasted Hawaiian pig feels like, also certain soils can be flammable.)

I have found that it's easier to pack some old towels and wrap hot rocks from around the fire, a rock the size
of your fist will last about 4 hours.(Be real selective about the rocks you use - Don't get any from a stream, if they have trapped water they
will explode!!!) You don't want it red hot but that is were the towel comes in to play if it's hotter then comfortable to the touch. This
works well if you place the hot stones by your kidneys. (This is also good if you have the military canteens/cup/cover - you fill them w/
boiling water and same kind of deal- just make sure you seal them good, water burns are no fun). The hot water deal doesn't last as long if it's really cold out. I've
slept out in about 30 to minus 15 in Pa. The hot rock trick was a life saver. Thank you Rob. I found some cool stuff on your site Mike F. (Thanks again Mike its enthusiasts like you that make Outlandish Outdoor Activities so much more interesting and comfortable. Comment?


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wilderness survival / navy seals

I agree with using the hot rocks. Several of them can warm up a small tent or shelter and keep it comfortable for most of the night. Be sure that you don't overheat the rocks either. The OP mentioned not using rocks from a stream and he is correct. Overheating rocks can cause them to explode also. Especially when you put them on cold, damp soil.

I do not agree with burying hot coals under your bed. Digging loosens up the soil, and when you are moving in your sleep they can work their way to the surface. The last thing you want to happen is to wake up on fire. If you bury them deep enough to where you can't get them back to the surface, coals aren't very effective.

I have used the hot water in canteen trick. It does work ok, but I don't like using it when sleeping. When I was in the Army, I used this on really cold days. I would fill my canteens with boiling water right before I went on guard duty. I would put my Parka over my pistol belt and canteens and on extremely cold periods, I would stay relatively warm. This has worked for me when staying outside in -40 temperatures for 2 hours. The reason I don't like it at night is in real cold weather the water only stays warm for a few hours. The rocks work much better.

I am assuming that shelter building was out of the question? Otherwise just build a shalter, fire
and a reflector. I've been out in -50 degree weather in northern Maine and had the temp in my
shelter up to a + 60 degrees.

Using rocks sounds like a some great tip. Sleeping on coals would be my last choice.