Combat Medic

Combat Medic is a companion perk in Fallout 4.

Obtaining
To gain the perk, the Sole Survivor has to reach maximum affinity with Curie after completing her personal quest.

One way to gain max affection is to send Curie to a settlement and get  Dogmeat as a companion. Then attack Dogmeat with a powerful weapon (such as a Gatling laser or minigun) and when he gets injured, heal him with a stimpak, which Curie will like. Then quick-save and quick-load, and repeat the process until max affection has been reached. This also gains the approval of other companions (such as Piper and Preston) as well so to get the most out of this plan, have other companions in the same settlement.

Effects
Once a day the player character can heal 100 Hit Points if their current number of Hit Points is below 10%.