Lake Michigan has frozen over after temperatures in the USA have plummeted down to as low as -40C, which is lower than the temperature in Antarctica.
This 'deadly polar vortex', as it has been called by some forecasters, has brought temperatures down to -17C in Chicago, where the coldest day in 150 years was recorded. Locals have even been told not to breathe deeply or talk outside because of the cold.
The National Weather Service said that people should try to keep their mouths covered as much as possible, and advised: "To protect your lungs from severely cold air, avoid taking deep breaths; minimise talking."
Bloody hell, that's some serious cold.
Lake Michigan is the world's fifth largest lake by area, and the largest lake that is contained within a single country.
The area, alongside much of the Midwest of America, is currently in the grips of a 'polar vortex' that has descended from the North to sit over the USA.
This means that people are in real danger. The other day, weather service meteorologist Brian Hurley told the MailOnline: "If you live up in the Arctic Circle, you'd say this is pretty normal. When it's actually brought down to this level, that's when you know it's something serious."
Another meteorologist, Tyler Hasenstein, added: "I think the proper term is nasty cold.
"We are very confident this cold is going to be significant... People are right to be concerned."
Of course, this has been causing absolute havoc with travel. Rail, air, and road travel in the area are absolutely knackered because of this period of seriously extreme weather.
Yesterday, this was predicted to be the worst that it would get. Still, that means that it is the coldest it has been for ages.
"The coldest air in a generation is sinking south, with below-zero temperatures already in the Upper Midwest," said CNN meteorologist Dave Hennen. "And the worst is yet to come."
Yesterday, Illinois Gov. JB Pritzker declared a state of emergency, stating: "There is a real risk of hypothermia and frostbite. Even five minutes of exposure can have very severe health consequences."
Meanwhile, over here we've been complaining about a bit of snow and sleet ruining our day because we've worn the wrong shoes.
Seriously though, stay safe out there, wherever you are.