You're absolutely correct. I should have been clearer.
When I mentioned the >2km 'elevation' I meant in an airplane, which typically cruises around 10km ... but are pressurised, as you note. Unfortunately they're pressured to be around 2.4km (effective). Some newer planes will pressurise to around 1.8km but these are uncommon.
In any case, water boils at '2.4km effective' at around 92C ... and therein lies the problem.
When I mentioned the >2km 'elevation' I meant in an airplane, which typically cruises around 10km ... but are pressurised, as you note. Unfortunately they're pressured to be around 2.4km (effective). Some newer planes will pressurise to around 1.8km but these are uncommon.
In any case, water boils at '2.4km effective' at around 92C ... and therein lies the problem.