Huh, strange. Isn't hair made up of the same stuff as the skin and nails? If anything I think the TV series got that part right and the books not so much. But then, well, magic gonna magic.
Also, lol @ this from GRR Martin...
Quote:
Granny: Do Targaryens become immune to fire once they "bond" to their dragons?
George_RR_Martin: Granny, thanks for asking that. It gives me a chance to clear up a common misconception. TARGARYENS ARE NOT IMMUNE TO FIRE! The birth of Dany's dragons was unique, magical, wonderous, a miracle. She is called The Unburnt because she walked into the flames and lived. But her brother sure as hell wasn't immune to that molten gold.
Revanshe: So she won't be able to do it again?
George_RR_Martin: Probably not.
http://25.media.tumblr.com/f3dbf7907...hp55o1_250.gif
I know he only says "probably" but it does show that he did not seem to intend on her being able to do that again, and can't offer the same excuse this time (unless there were dragon eggs around that I couldn't see).