This TED Talk explains how Lewis Pugh defied the "impossible" by swimming a WORLD RECORD distance in the North Pole waters. Through sheer determination and dedication, Lewis Pugh achieved this amazing feat. Now the reason he did this feat was not only to follow his dream, but was also to inform people and political leaders about the climate change. To show them he swam in "frozen" waters in the North Pole. Now he shouldn't have been able to SWIM these waters because normally the water is supposed to be completely frozen over, and not melted. The climate's changed so much that 23% of the ice that's supposed to cover the water is gone, and melted away.
I found this TED Talk informative yet amazing, and also inspiring. He talks about how he prepared mentally and physically for this task for multiple days. By the time he got to the location he was pumped and ready to do go. But his body was so unprepared for the icy waters because it was THAT cold (1.7 degrees celsius, almost at the freezing point). His body swelled up, and he was in so much pain. He overcame these obstacles and pushed through it, fulfilling a dream.