A video from Canada of YouTuber Viva Frei throwing a huge pot of boiling water into -29 degrees Celsius air on Saturday, creating a giant cloud of ice.
"What do you do when it is so cold outside they're not letting the Penguins out at the Calgary Zoo? You take a massive pot of boiling water to make the biggest Mpemba effect ever!" Viva Frei wrote online.
The Mpemba effect is named after Tanzanian Erasto Batholomeo Mpemba who observed that in some circumstances warmer water can freeze faster than colder water.
