I was thinking that there should be a first aid book. It should only have 1 skill point. And all the book would do is teaching the player to revive a person when they are dead. It should have a 50/50 chance to revive the person, and then have a delay about 2-3 minutes before it could be used again.
I come to think of it as when i play there is no EMS, and many people know how to do first aid today.
You could add more skill points for the book, and make the chance to revive bigger.