Ζεστός is an odd word, it can mean warm or hot ( both are accepted here). I like the phrase "Πο Πο ζεστή" (Sp?) useful on a very hot day - a quick path to sounding Greek!
Yes, it is odd. πο πο τι ζέστη Of course, there is always καυτό (καυτό σίδερο hot iron).