That could be very dangerous in wooden buildings. Aside from the cooler, it's only really useful around metal and rock, in situations where he can't just touch things. I don't think he needs to avoid leaving fingerprints anywhere, so it's basically down to learning about the ceilings of buildings in the Fire Nation and Earth Kingdom.

Oh, and spotting rocks being bent at him. If he kept his fire going all around himself, then when a rock came toward him, it would reach the fire and he'd know to dodge.