Since the game is on the basis of realism and it's considered there will be a kind of hearthstone, perhaps it could be called Smoke Bomb or something. It would be a consumable with a 1 hour or so cooldown. Once used you lose it. So it's important to bring many with you at a given time. I just think part of the game difficulty is that you should be ready for this kind of situation. And I think only 5 should be held at a time or something as well so people aren't making Smoke Bomb empires or anything
