Lewis Pugh took the plunge and became the first man to swim at the North Pole!
The 36-year-old Londoner spent almost 19 minutes at minus 1.8C as he front crawled for a full kilometre - more than half a mile in the coldest water a human has ever swum.
"It was like jumping into a dark black hole," he said. "The pain was immediate and felt like my body was on fire.
"I was in excruciating pain from beginning to end and I nearly quit on a few occasions. It was without doubt the hardest swim of my life."
But he said that a colleague ski-ing on pack ice alongside him looking out for hungry polar bears spurred him on.
Link - Thanks David R!
I once swam in a lake in May (where I live, the water is freezing that time of year, but not frozen.) and it was so cold I got a brain freeze, so I got out. But it was COLD.