He could sometimes be dense, but Bobby was far too used to seeing other mutants hunted down--of seeing the look on humans' faces who just didn't understand--to not immediately recognize the fear in the other boy's eyes. It was, perhaps, because of that fear that he wasn't going to turn and run when things started to get more dire.
Oh, who was he kidding? Bobby was too much of a good guy not to play hero. Of course he was going to stay either way.
The reaction was immediate to the rushing wind as his body temperature dropped immediately. Flesh and bone converted to solid ice--if it were a battle, then he damn well was going to face it in the form he could actually rebuild if it got damaged. Gritting his teeth, Bobby advanced forward, stretching a hand toward Stiles. "Put him down!" he yelled. He didn't want to use his ice against the guy if he could avoid it. If he could avoid appearing hostile to someone who was obviously scared and unable to control his abilities, then...
He may have, perhaps, been a bit idealistic. He didn't know, after all, what the guy's true nature might have been.
"I know someone who can help you!" he continued earnestly. "He can help you control this!" Again, there was that idealism. In his mind, Professor X could do anything. THe fact that this was a younger Professor didn't even occur to him.