Efficient Masseur (5e Feat)
From D&D Wiki
You've learned how to apply your training on a whim, and while resting. In combat, you can make a medicine check versus a persons constitution as the DC. If you succeed, you can apply one of these following effects:
The person gains 1 AC until the end of combat, and cannot be affected by Efficient Masseur until this effect ends.
The person regains half of your medicine modifier in HP.
The person gains temporary HP equal to your medicine modifier.
You can also apply your training during times of reprieve, during short or long rests, you can spend an hour to massage a creature thoroughly, applying one of the following affects:
The person gains advantage on the next dexterity save, or check, they make.
The person regains an additional hit die for half of every hit die they spend, rounded up.
The person gains the benefits of a long rest after only 3 hours of additional rest.