to make it even more egregious:

"Quick! Climb to about 1000 feet above sea level and the trex will boil and we will be safe!"

I know you were talking about a mountain or something, but "climb to <altitude>" does make one think about this exchange which would be in feet, not meters:

"climb to FL20 and the flying dinosaur thing will break" could work though

Since, annoyingly, international altitudes are done in increments of 1000 feet (ish, handwaving)