Forgive me if this has been answered, but are evil clerics immune to their own channel ability? The rules say the negative energy is a burst centered on the cleric, so clearly they would be inside of the area. It seems logical to me that if a good cleric channels positive energy and can heal themselves with it, then an evil cleric that channels to harm the living would also be affected by the ability - though would get a Will save for half damage.
This might also be a problem for an undead cleric who happens to be good.
From the PRD: "A cleric can choose whether or not to include herself in this effect."
Ah, missed that. Thanks.
If you take the Death Domain then at 8th lvl negative energy will heal you in the way that it does undead.