Actually I suppose you could mishandle some liquid nitrogen and experience something close to absolute zero. It wouldn't be a pleasant experience.
And gutted, I've never played a scale without playing the entire octave, which includes the top note. Actually what your brain evaluates is the 12 intervals, NOT the 13 semi-tones. If you leave off that top note, one octave above the first, you lose that last half step interval that defines the major scale.
Also, if you detune the entire scale by any number of hertz but keep the same intervals, the music sounds fine and you'll probably not even notice. I do that all the time with my chronotron to tune recordings for singers' ranges, although usually I'll transpose by an even number of halftones just out of habit. If I encounter a singer with perfect pitch and don't restrict myself to that convention, they get all discombobulated.