Hottest? No idea. I’ve never liked the heat and avoid it when I can.
Coldest? Easy. Forty feet (12 meters) up on top of a jet fuel tank in Thule, Greenland helping to change the cover on an automatic tank gauge. It was in the -40s on the ground (doesn’t matter which scale) and windy. I don’t know how much colder it was on top of the tank, but it was certainly colder than it was on the ground.