Some of the Marvel characters; like Wolverine, Deadpool, Sabretooth and The Hulk to name a few ; have an accelerated healing factor,which helps them to recover from life threatening injuries in minutes. It also makes them resistant to any forms of poison, toxins or dangerous chemicals. read more
Laughing gas don't make anyone happy. It does irritates as it force out body in doing something which we don't want. So forcing Hulk body doing something he don't like will make him more aggressive not calm. read more
The dull pain not completely shadowed by the former flow of gas, bothered him less. In fact, he'd gotten rather used to it. Something else really bothered him about what they were doing. read more