I guess I just don't have those situations where people keep coming to me and asking me for help over and over again, but even then if there are those people you can sit them down and explain to them to not do that without snapping at them.
I've had people snap at me occasionally (not because I was asking for help, more because they were assholes in the course of doing their regular job) and the only thing that happens is I avoided them and kept a written record of the times they'd been unpleasant in case we ever needed to talk to HR.
That being said, I don't think it's an eventuality that people will always get frustrated with other people. I've never had anybody inspire "rage" in me in work situations. Other than some times I was working on tv sets and people were screaming.
