Sleeping in an "igloo"

I can cross this one off my bucket list now, well, after I make one.. Me and my brother decided to brave it out last night in our snow fort. Now, as you can tell from the high quality picture above we were both prepared, we had huge thick blankets, sleeping bags that were made for ten below, mattress pads fit for a queen, hats, gloves, wool socks, the whole nine yards. We both fell asleep fairly quickly, but it was only for an hour. I woke up to the horrid feeling of a chill on my back, my sleeping bag had come unzipped again. And from that point forward I was an icicle! I could not get warm again no matter how hard I tried, finally at 3:30 I fell back asleep for another hour or so, the next time I woke up buddy was up too, we compared notes, shared warming techniques and were back to sleep all nice and warm. We ended up braving it until about 6:30, we both had to go to the bathroom and both wanted to go to sleep in our actual real beds. The moral of this story: use hand hotties.