In case the reference is lost, there's a famous Muslim proverb: if the mountain won't come to Muhammad, then Muhammad must go to the mountain. A flipped version of this proverb has somehow also become commonly known, perhaps surpassing the correct version (in my culture at least): if Muhammad won't go to the mountain, then the mountain will come to Muhammad.
I just want to know what kind of thermometer they put into the plasma to measure the temperature. It must have been made of ice or something to not burn up.
They usually measure extreme high temperatures differently, not with thermometers based on heat expansion of materials. They measure heat radiated, not conducted.
In plain English, they look at it with a heat camera, like you see on TV they patrol borders with.