I would suggest that certain places on the map, either toxic or radioactive, to explore it for loot at these locations, need proper equipment.

And in the game, has small missions with rewards you with loot after complete it, like, appears a character on the map to take him to the extraction point, or even mission which has to recover certain object and takes it to some local.

The reward could be left equipment on site after completing the goal, or even a vehicle.

Sorry for the English by Google, I hope you understand what I wanted to spend.