How do you handle them?
I treat hit points as the abstract figure they are. For the most part, a successful 'hit' doesn't actually hurt the character at all, but still subtracts from their hit point total. Grazing blows are landed once then player is below double their first-level hit points. Wounds start actually being inflicted once they go below their first-level hit points (this is when blood is drawn, so fights until first blood and so forth last more than a single swing).
This causes issues, of course, with injected poisons and so forth, but for those I just wing it. If the blade is coated in an injection poison, I'll have the hit that delivers the poison draw blood. If something falls on someone pinning their leg, I'll have them actually get hit despite their hit point total.
I just think it adds a little more to the game, and doesn't mean that a tenth-level fighter can take a sword to the gut moreso than a first-level fighter -- but that first-level fighter who's got some amazing toughness and a hardy constitution can still run around with a huge gaping wound in his chest, whereas the tenth-level finesse fighter can duck and weave like mad but that one blow does him in.
Do you do something similar, or do you treat them as they are classically handled?