question:  What likely caused the most problems?
context: He had no stomach for mysteries, vast or trifling, and there were pressing things to think about at this time. Across to the right was a group that Baron knew vaguely—Andean climbers, or at least two of them were. Then he settled back and waited impatiently for the intruder who demanded his time without justifying it. I guess I was about ten when Wyatt and Carpenter made the last attempt—that was in 2082, I think. I know now that they were a pair of idiots, starting off without proper equipment, with practically no knowledge of surface conditions, without any charts—they couldn’t have made a hundred miles—but I didn’t know that then and it was a terrible tragedy. After that, I followed Sanderson’s work in the Twilight Lab up there and began to get Brightside into my blood, sure as death. Too many men in this game are all nerve and luck, with no judgment. “I want to make a Crossing at perihelion and I want to cross on the surface. The Twilight Lab, near the northern pole of Mercury, was the obvious jumping-off place. The setup there wasn’t very extensive—a rocket landing, the labs and quarters for Sanderson’s crew sunk deep into the crust, and the tower that housed the Solar ’scope that Sanderson had built up there ten years before. F. No permanent installation with a human crew could survive at either extreme. But with Mercury’s wobble, the twilight zone between Brightside and Darkside offers something closer to survival temperatures. Sanderson built the Lab up near the pole, where the zone is about five miles wide, so the temperature only varies 50 to 60 degrees with the libration. The Solar ’scope could take that much change and they’d get good clear observation of the Sun for about seventy out of the eighty-eight days it takes the planet to wheel around. The Major was counting on Sanderson knowing something about Mercury as well as the Sun when we camped at the Lab to make final preparations.
output:  the high temperatures
options:  the toxic gases  the high temperatures  vehicle trouble  incorrect mapping