Zona Medicina is the ability of the Médico Supremo. It releases a healing cloud that doubles health regeneration for you and nearby allies, and with a full charge it can bring you back from a killing blow.
Activate it and a large cloud of healing gas appears. You and allies in it regenerate health twice as fast. It gives you a quick fix when you are out of medkits.
Reach rank 4, Espía, then buy the Médico from Juan with Depleted Uranium.
Very good solo. If the Supremo is fully charged when a hit would kill you, you can use it to revive yourself and keep fighting. In co-op it also keeps your partner alive.
Speed Surgeon makes your manual heal recharge faster, so you have two ways to recover in a long fight.