[With the fire as a base, Iroh gets into a more formal stance and proceeds to breath in and out. As he does so the fireplace gets noticeably hotter, and the fire itself bigger. He then proceeds to create a small ball of fire in his hand and simply holds it near to the back of some of the apparel not in the way of the heat]

It might be a little less showy then you were expecting, but one must be very careful of fire. Much like the destructiveness of man, a fire can quickly consume far more than intended.