There is nothing unusual about records being broken on Mount Everest. But last week, two sets of climbers turned heads with ascents that many had never thought possible: they went straight up from sea level to the world’s highest summit in less than a week. On Wednesday, a team of four UK climbers, all ex-special forces soldiers, summited Everest having landed from London just over four days earlier. The following day, US-Ukrainian climber Andrew Ushakov said he had gone from New York to the top of Everest in under four…