Americans have been warned to stop trying the "boiling water challenge" after several cases of people being burned.

With large parts of the US hit by a deep freeze last week, some took up the challenge to throw water in the air and watch it instantly turn into frozen vapour.

The stunt, during the so-called polar vortex, has gone viral - and while it may look like an interesting science experiment to create clouds of steam, several people ended up in hospital as the wind blew the boiling water back on them.

#boilingwaterchallenge the other day in the #PolarVortex but I threw the water all over myself and everyone else. pic.twitter.com/js7B4uyf0Y — Adam Bishop (@adammbishop) February 3, 2019

Chicago's Loyola University Medical Centre said it had treated eight people who tried the exercise.

A spokeswoman said the hospital had seen injuries to the face, hands, arms and feet - as well as "varying degrees of burns". Onlookers were also among the victims.


Dr Arthur Sanford, a trauma surgeon, warned people not to perform the stunt as "there is no safe way to do it".

One person was treated at the University of Iowa Burn Treatment Centre in Iowa City, and Hennepin Healthcare in Minneapolis said a couple of people have been treated there in recent weeks.

Angie Whitley, the clinical care supervisor at Hennepin Healthcare's burn centre, told CNN: "Some of them being parents or adults (who) go outside with their kids to do it, and the kids kind of get excited and step in the way, and the parents end up throwing the water on the children.

"Or, people throw it in the air just as a gust of wind comes, and [the water] catches the wind and it blows it back on them - so we see some face scald injuries from that."

The polar vortex which normally pushes strong winds around the northern pole has sent an icy blast southwards in the last couple of weeks.

On Wednesday last week, International Falls in Minnesota was among the coldest places in the US.

It recording a low temperature of -38C (-36F) on Wednesday with a wind chill factor of -48C (-55F).

Meanwhile in Russia, residents of the Ural region and Siberia, where temperatures recently fell to -40C (-40F), have also been attempting the stunt.

Hundreds have posted photos and videos under the hashtag #dubakchallenge - showing people throwing the boiling water up which instantly condenses into an elaborate pattern of ice crystals.