Witnesses and sentinels of the upheavals occurring on a global scale, the poles have become major natural laboratories for researchers studying climate change. But these icy extremities have always been as fascinating as they are inhospitable. The conquest of the Arctic and Antarctic was long and perilous. Many advances were made only thanks to the tenacity of the first adventurers. This journey to the ends of the earth offers a scientific investigation in the footsteps of the conquerors of these icy poles, with insights from Sophie Berger, glaciologist, Jean-Louis Etienne, adventurer, and Jérôme Chappellaz, director of the French Polar Institute Paul-Emile Victor.