You may have heard: the United States is in the midst of one of the worst periods of cold temperatures to hit the country in decades. At least 21 people have died in icy temperatures that have plunged to -46 degrees Celsius wind chill (-51F). Around 250 million Americans across the Midwest region are being hit by the polar vortex weather phenomenon – with a number of them posting impressive photos and videos on social media showing just how cold it really is.

Social media is filled with videos of people doing the boiling water trick. In below freezing conditions, if boiling water is thrown up in the air, it freezes before it hits the ground, turning into an impressive snow cloud.

Do you like your pasta al dente? This photo of someone’s lunch in Chicago was posted on Reddit and went viral. The noodles have frozen, fixing the fork in place in mid-air.

Wet clothes freeze instantly, making creepy scarecrows that can stand up by themselves in the snow.

Don't have any tools to hand? In Minnesota, you can just use what’s in the fruit bowl – in this case, bananas that have frozen solid.

Also in Minnesota, someone is going to have to rebuild their toilet once temperatures are back up to normal.

Frost is gathering inside houses.

Bubbles freezing? Not so fast

While there are some amazing pictures and videos coming out of the polar vortex, some things circulating are faked, or not recent at all. This video below was retweeted over 3,500 times. It show a man blowing bubbles outside in snowy weather. The bubbles become opaque as soon as they are formed, and float slowly through the air. The caption says that they’re freezing.

But this video doesn’t have anything to do with the US polar vortex. It was posted on YouTube in 2017, with the caption saying 14° Fahrenheit – that’s only -10°C, nowhere near what some people in the US are experiencing right now. Most crucially, the bubbles aren’t turning opaque because they’re freezing: it’s a simple trick that involves the man vaping beforehand and blowing vapour into the bubbles so they seem denser – but in reality they’re just filled with vapour. The video has also been slowed down, which makes the bubbles float more slowly and seem heavier, and it means that when the bubbles burst at the end, it looks like they’re shattering slowly when in fact they just burst quickly like any normal bubble would.