A character proficienct in healing knows the basics of first aid and medicine.
With a successful proficiency check, a proficienct character can restore 1d3 hit points to a creature just wounded (though they cannot restore more than the creature lost in the last round). A creature can only benefit from this healing once per day.
A wounded character who is cared for by a proficient character can recover 1 hp per day even when traveling or engaging in basic activities. With complete rest, the character can recover 2 hp per day. Combined with the herbalism proficiency, a resting character can recovery 3 hp per day. A proficiency character can care for up to 6 characters at one time.
A proficienct character can also treat a character poisoned by injury - if they reach the poisoned character in the round after poisoning, and continues to care for them for the next 5 rounds, the victim can delay their saving throw until then, and then gets a +2 bonus to the save. If the care is interrupted, the poisoned character immediately rolls a normal saving throw. A character with herbalism and healing can treat swallowed or contact poison (typically by preparing a purgative).
The proficiency can also be used to diagnose and treat diseases. A successful check reduces the disease to its mildest form and shortest duratino. Herbalism proficiency grants a +2 bonus to this check. A successful check can also diagnose a magical disease, but only magical healing can cure them.
CP 4, Initial Rating 5, Wisdom (Intuition) / Charisma (Leadership)