Water can boil and freeze simultaneously under specific conditions.
Why it is true
At the so-called triple point, the exact temperature and pressure allow water to exist in all three physical states at once.
Source: Physics Today
Would you rather be asked first?
This is the reading side of the site, so the answer is in the sentence above — that is the whole point of it. Test yourself works the other way round: the question comes on its own, and the fact and the explanation only appear once you have answered.