[quote=@FalloutJack]
[@Balthazar007] A thought: If exhaustion is affecting health, you may want to add a proviso that you aren't likely to exhaust yourself to [i]death[/i], and that you're mainly stunned if you conk out, whereas someone trying to kill you is a bit different.  
[/quote]

I've thought about that, and this shouldn't be a problem. When your health falls below zero, you simply are Knocked Out. Unless, your health falls bellow the absolute value of your character's MAX HEALTH. For example, your characters all currently at 110 health. To die, you would need to be fall below -110 health. Until then, you're just unconscious and defenseless. 

In a non-tournament setting, if you don't have allies around to protect you while you're knocked out. An enemy can apply a finishing blow.