Awesome little kit, tho no means to make the mixture cold. You could simply tuck the container into a freezer, or better yet the little slot where the ice cubes are jet-frozen. Or you could have one of thems chemical ice-packs.
Then again, if I’m in such a situation where I’m using a candy tin as a shaker and a piece of paper as a glass, I would say that a quick snort off a hip flask filled with gin and vermouth, or just gin…or just about any distilled spirit would get me out of whatever hardship I’m in with less effort.
Still I admire the ingenuity. Also the little plug made from a water pistol is AWESOME!