Distrust

At first glance, this achievement is quite daunting. Normally, you can only rez someone with an adrenaline shot. Those shots tend to be in short supply. I've gotten around 3 total shots per game.

However, there is a way around this limitation.

First, you need to unlock the character Phillip Strauss. This is done through completing the game at least once and you'll want to get the Secret Ending to unlock the third character slot (Secret Ending is not really necessary as you can still do this with just 2 characters, just takes longer). Why do you want Phillip as one of your characters? Because his special ability is to rez without using an adrenaline shot.

See where I'm going with this?

Start the game. Put your second & third characters (preferably ones with low cold resistance) outside of a heated building with Phil inside the building. Wait. While waiting, Phil can go around scavenging stuff, just to break up the monotony. Eventually the second and third will collapse as their health runs out. Take Phil over to them and rez them using the CPR symbol that Phil gets when clicking on a downed person. Repeat 15 times to get the achievement. You may have to save & quit if you run out of food for Phil before you finish rez'ing the others the requisite 30 times.

Bleep bloop. Achievement unlocked. Hope this helps.