Amazing footage from the US shows Americans turning boiling water into "snow."
As a polar vortex grips parts of the US where temperatures have dipped to a record-breaking -32C in Chicago, a new social media challenge has followed in its wake.
Incredible videos show people braving the frigid temperatures to throw boiling water into the freezing air where it instantly turns into a cloud of flakes.
“#Chicago is so cold right now that hot water turns straight to snow,” tweeted Eylon Levy, along with a video showing him throwing a mug of water over a balcony and the liquid flaking out.
According to National Geographic, the trick occurs because the tiny droplets of hot water start to vaporize: “Since cold air can't hold as much water vapour as warmer air, the water condenses. Extremely cold temperatures quickly freeze the water droplets, which fall as ice crystals.”
Some people have been extra creative with the experiment, filling a water gun with boiling water to shoot over their backyard.
Others have filmed other cold-weather spectacles such as floating frozen soap bubbles.
But, the winter experiment comes with a warning: take wind direction into account when throwing boiling water around.
In 2014, at least 50 people were scalded when attempting the trick in -30C temperatures.
Others have filmed other cold-weather spectacles such as floating frozen soap bubbles.
