The phrase "on the hot seat" implies that a coach either has a good season--playoff appearance, playoff win, for example—or they get fired. And make no mistake about it, there are a few head coaches out there in that very situation.
But there are also a handful of coaches in the NFL who, although not exactly "coaching for their life," can't keep resting on their laurels from the past.
And although they all got to this point different ways, all have different styles, and different approaches to the game, for both those subsets of the NFL coaching fraternity, 2011 is an enormous season.
Time to step it up.