From Pathfinder Lost Omens Hellfire Dispatches, which isn't enabled.

Godless Healing

FEAT 2

Prerequisites Battle Medicine; can't have a patron deity

You recover an additional 5 Hit Points from a successful attempt to Treat your Wounds or use Battle Medicine on you. After you or an ally use Battle Medicine on you, you become temporarily immune to that Battle Medicine for only 1 hour, instead of 1 day.

Pathfinder Lost Omens Hellfire DispatchesORC