Meh, it happens to everyone at least once. My first time I swapped out an item that had my CON bonus on it and that dropped my HP low enough to die. Everyone in my party laughed (including me) and called me a noob (including me) and I learned. I have seen a few "end of rage" deaths as well and they never cease to entertain. Don't let yourself get that low on HP is the only sure way to prevent this.