Did you know you can purchase a liter of liquid helium for only $30
liquid... Helium? I'm sure (not looking at Wikipedia) that a few years ago I found out that Helium is the lowest-temperature liquid element there is. It needs to be cooled to absolute 0 to become a liquid. However, when it does it has this weird phenomenon where it can go up the side of containers if the other side of a rim is lower than the area it occupies.
Also making any physical contact will result in whatever you touch it with getting frostbite to such an extreme degree that even your blood would solidify.*
*keep out of reach of small children.