Hammock camping out in the snow can get a little chilly. Ideally you want a little tent stove/heater. I made these little stoves and actually sold a few for a short time. They work pretty good but need to be fed constantly, unless you stack rocks around it as a thermal mass.
Smoke is flammable, and will catch on fire when trapped in a confined space. I tried to utilize this technology by creating a multi-chambered stove the would re-burn cleanly without smoke.
A while back, I made this rocket stove out of concrete. I found a cast iron trivet to act as the grill. Seems to work pretty good.
