Given that phase change captures a ridiculous amount of energy (it takes roughly 5 times as much energy to go from liquid water to steam than it takes to bring that same water from 0C to 100C).
I've always wondered why we don't optimise CPUs for running at ~101C.<p>And as long as there is material to phase change the tempersture will be fixed at the phase change temperature, so boiling water will never go above 100C at 1bar.