Would you be able to reset your life to 13 after the combat damage is dealt if the total was a lethal hit to a player as part of the stack?
What exactly is the situation? Under normal circumstances no, because losing the game from having 0 life or less is a state-based deal - if you are officially at 0, it doesn't matter what's on the stack or on battlefield anymore, you be dead. Plus it's hard to respond to the combat damage when you're dead.
But this is all assuming there's no {platinum angel} type situation letting you live through 0 life. If that's the case, sure, respond and stack away!
You can respond before damage is delt