Water can boil and freeze at the same time.
Can it really? It can boil and freeze at the same temperature, but that isn't the same as it boiling and freezing at the same time.
That would be sublimation, well not quite. That would be the triple point.
True, its a function of temperature and pressure.
My dad told an "it was so cold" yarn about throwing a pot of boiling water out the door on a cold winter morning and it froze before it hit the ground, he went to pick it up and it scalded his hands.
I've never heard of anyone doing that last part before. Perhaps the surface freezes and it's still next to boiling on the inside of each "frozen" drop.
@David_Cooper It is just a story with no truth to it.