Some time ago a friend asked me how I would build a shelter if for some unknown reason a day hike turned into a night or so in the woods with no tent-tarp or sleeping bag. So yesterday I finely got the chance to get some dirt time in and make a video. Ive been making these types of shelter since I was around 9 years old and think they are the best natural shelter that a person can make. You need no tools and use what is found on the wood land floor. One thing I learnt when I worked as a gardener is that rotting leaves give of heat and once your Debris shelter has been up for a few hours you will start to notice the warmth of the leaves this is because they are being broken down by micro organisms,They obtain energy by oxidizing organic material,This oxidation process heats up the leaves from ambient air temperature. If proper conditions are present, the pile will heat up fairly rapidly due to bacteria consuming readily decomposable materials by the micro organisms. YouTube - Debris shelter.