Half or reduced healing

[Fot5]

Is there any way in the 4e ruleset to reduce the amount of healing that is applied by a PC to another PC? For example, say you've got an area where all healing is reduced to half of what the power indicates. Is there any way to apply that to a roll or power application?

[Griogre]

You have to do it manually, for half healing. For reduced the player can put a negative modifier in the mod box. This works well with healing potions.