You can already buy shirts and other garments specifically designed to keep you cool while battling the heat, but they're no where near as revolutionary as this refreshing Cold Foam. It comes ready-to-spray like a can of silly string, and once released the foam immediately chills to just over 1 degree Fahrenheit, and stays that cold for up to five minutes.
It also solidifies and hardens after a few seconds, letting you mould it into wristbands, headbands, or a cooling compress. With enough cans you can probably even make yourself an entire suit out of the stuff, but at $8 each that's an expensive way to battle heat stroke. Particularly when the cooling effects wear off and you're left coated in an uncomfortable layer of blue foam. [Rakuten via Technabob]