There is no difference in temperature between something that is just simmering, something that is boiling slowly and something that's a rapid boil.
When someone pokes a button in you, and you get scared and say leave me alone, grump grump grump ... it's exactly the same as screaming and throwing things and attacking people. It's that place where you go from "I'm in control" to "I'm out of control and angry". Just like the boiling water, when you shift from one to the other, it doesn't matter if it's a simmer or a slow boil or a fast boil where you're attacking people with knives.
Any time you find yourself shifting from being in control and making your own decisions to the fear and anger taking a hold of you, you've already got a problem. Don't wait until it becomes a raging boil before you consider it a problem and address it.