Haven's Helpers In Ground Stove. The HHIS is an all terrain stove that can be built for less then $100 dollars. This manual tells you how to make the stove from top to bottom. Along with pictures that demonstrate what is being done in each step. The HHIS allows you to bury the stove in the ground to keep a small fire signature with all natural fuel. This is one stove that you can be without in your Haven Helper's Handy Sack (AKA Bug Out Bag).