Re: freezing temperature of brine and pressure sensitivity, of course it is sensitive but we are talking about MPa-GPa of pressure, way beyond small pressure changes due to changes in altitude. You can get started by looking at physical chemistry of solutions if you are interested! A good place to start is “freezing point depression” and “boiling point elevation” of solutions. Also, single component phase diagrams: here it is for water.
So I was a little off on the temperature chosen for the body, but the Wikipedia page has some good details: https://en.m.wikipedia.org/wiki/Fahrenheit
Re: freezing temperature of brine and pressure sensitivity, of course it is sensitive but we are talking about MPa-GPa of pressure, way beyond small pressure changes due to changes in altitude. You can get started by looking at physical chemistry of solutions if you are interested! A good place to start is “freezing point depression” and “boiling point elevation” of solutions. Also, single component phase diagrams: here it is for water.