Why is the sky blue?
Why is the grass green?
Why do we hiccup?
I don't know. the only think that's important is that it is what it is. Zuko's hot. There is no specific reason for it; he just is.
(Plus, he's, you know, a firebender. It's in the job description.)
i dont know!!! he just is!! and we want 2 keep him that way, rite? lets just let him be hot and move on with ower lives. (not meaning move on from zuko!)