Well that dwarf sure wasn't long-lived

. So how does the rules work about 0 wound points? Am I unconscious? At what point is death knocking at the door? Can I still smash a skull before I go?
It's actually not
too bad. Norgrim is now very badly wounded, and it will take a matter of weeks to heal unless he receives somewhat costly medical (or even more costly mystical) treatment. He's still able to stand and fight at full capacity, although subsequent wounds are extremely likely to reduce his capacity to fight and/or breathe.
Anyone--Norgrim himself included--may take a full action* to attempt to heal him with the Heal skill, available only to those who are trained. In your current condition, a successful check would net him 1 precious, precious Wound point. Applying a poultice, if you had one, would allow a heal check to restore 1d10 points. Such a check may be made once per battle in which you receive wounds. The following day you may receive the benefits of another Heal check, and once per day thereafter.
Of more pressing concern in the here-and-now, however, is the greatly increased risk of injury to Norgrim's person. When you take damage greater than your current Wound points, that number determines a roll on the Critical Hit table, the very mention of which should make Norgrim quiver in his tattered dwarven boots. As a random example, the next successful attack on Norgrim might
...roll a few dice...reduce Norgrim's left arm to a dangling mass of meat, and although his shield would remain strapped to his arm, blood loss would have a 20% chance per round of killing him unless he received immediate treatment. At the end of the battle, Norgrim would have to make a successful Toughness test or lose the arm from the elbow down.
Fun, eh?

Luckily for Norgrim, he also has two Fate Points, which may be permanently spent to avoid loss of life or limb. You can always spend one, even if circumstances make a character's survival nonsensical. The burden is on the GM to provide a reasonable
Deus Ex Machina.
*The rulebook says that skill uses vary in duration, and is completely mum on how long it takes to attempt a Heal check. A Full Action is my own ruling, and nothing more.