You could just have your team's Doctor make a Hard Medicine check and lose 0 sessions
Or you could have your players not fight at all and just have them pet puppies each session.
"If you can't take a bloody nose, Picard, you better crawl under your bed and hide." -- Q
Anyways, having all that said, let's not forget that critical injuries are always optional -- the GM never has to spend advantage to score crits against players unless he wants to. I'm not sure everyone appreciates what an elegant weapon that is. It means that players in the demesne of a narratively-minded GM have don't really need to worry about losing their hands, kneecaps and pancreases to a group of stormptrooper minions in session number one. But when you're facing down the Big Bad and death is on the line, are you really going to be crying about your beautiful face?