DCnU J'onn has had rather good showings against fire, though, if memory serves.
Limited Edition Flamethrower Batman got raped, for example.
The splash page with him taking on the whole team of Justice Losers was nice, too.
...
And then... then... uuh... OH YEAH! He got his nose busted up by Midnighter!
And DC execs are surprised why the ship is sinking.