I don't know if this was ever really explained in the comics (I was only just a casual fan),but how come GR's flames sometimes set things on fire,melt metal,but other times he could come close to, even touch things and people and they seemed to be pretty much unaffected?
shareEven though this comment is about a year old, as a dedicated comic nerd, I will indulge you with a response!
If I'm right, Ghost Rider's flames aren't earthly or natural, they're magical/spiritual in nature, and thus only burn what he wishes them to. They can have the same effect as real, physical fire, or cause emotional/spiritual pain as well. But again, I'm not really a fan of the comic character as much as I am of other Marvel guys.
"Bulls**t MR.Han Man!!"--Jim Kelly in Enter the Dragon