Bhutagni is the third dimension of fire. The other three fires are Jatharagni, Chitagni, and Sarvagni.
The next dimension of fire is called bhutagni, the elemental fire. If your elemental fire is on, the circus of the body and mind will not make much sense to you. Your interest and focus will shift from the antics of the body and mind to a more fundamental aspect of creation – the source of life. If you take charge of jatharagni, you will have a healthy and robust body. If you take charge of your chitagni, you will have a mind that you can use in many ways. If you take charge of your bhutagni, you will have fundamental mastery over the process of life.
The boundaries of the body are very clear and limited. The boundaries of the mind are larger. For example, if you know something about another part of the world, it is within the boundaries of your mind. As your knowledge expands, your mental boundaries can expand. But if you become conscious of the dimension of bhutagni or the elemental fire, you will be a boundless being, because the play of elements is happening across the entire creation.