There is an excellent discussion of spicy vs. hot at this question.
However, having read it, I did not see any answer that tells how to say unambiguously that food is hot (temperature) without being misunderstood.
If I say that my food is spicy, a listener will unambiguously understand that I am referring to the sensation associated with eating.
However, I can't think of a good way to say that my food is hot (temperature) without a listener possibly thinking that I mean spicy.
In the referenced question, a poster described how to unambiguously say that food is spicy. How can I unambiguously say that food is hot?