User blog comment:EvanDude345rv5/Fairy Tail 3 chapter special Part 2/@comment-4700320-20130717141132/@comment-5580383-20130719180212

I said it was similar to  Ice Shell, not  exactly Ice Shell. This is a much larger scale of this attack,especially considering the size of the town being 10 times larger than a average town and the giants  10 times larger than  average humans so it took up a  pretty large scale.

Natsu's average flame temperature is roughly 1773.15 kelvin, enough to melt  steel and  Iron and  even with that temperature, he can't  melt something that is  2180 K.

Good question, we can probably  argue that Wendy might   resist it  given she's a Dragon Slayer but Lucy is inexcusable, especially when she was never shown to  resist cold temperatures. That's a minor continuity error that i hope is corrected soon.