Imagine this scenario: You’ve just come out of a firefight, exhausted but unscathed. Coated in sweat and dirt, you reach for your standard-issue canteen for a swig of water — or, if you’re lucky, something a bit stronger. But hot damn, you’re fucked: A piece of shrapnel or spare bullet has punctured your canteen, spilling your water or whisky onto your uniform. Your thirst will go unquenched.