Source: Tal'Dorei Campaign Setting Reborn

Your body has the ability to recover quickly from terrible injuries, and is unusually receptive to healing magic. You gain the following benefits:

• Increase your Constitution score by 1, to a maximum of 20.
• When you are successfully stabilized while dying, you regain hit points equal to your Constitution modifier (minimum of 1).
• Whenever you regain hit points as a result of a spell, potion, or class feature (but not this feat), you regain additional hit points equal to your Constitution modifier (minimum of 1).