Er, you do remember what ceffect field does, right? It is supposed to affect a group of characters. Either all, or per building. I'm not talking about dummies.
No matter where MC is, when he uses it, it should effect him too, since he's kinda in the middle of the effect. And characters cannot use such items anyway.
But even if MC is in a building, it doesn't affect him, only characters. While in some cases it's useful, in others it's not good. It can easily be fixed by jump to label that heals him too. But I wonder if you prefer a more global solution, ie changing field mechanics.
Why not?
Can't guarantee full heal for anyone who has more than 10000 hp. Doesn't matter atm, might be a problem in the future.