As the thermometer rises, it first goes past "Freezing" and then, a little later, past "Melting". Actually the freezing and melting points of water (or anything else for that matter) are always the same. The only difference between "freezing" and "melting" is in the "direction".
The Tyrannosaurus Rex looks nothing like a real T-Rex, whose appearance was fairly well known by 1942.
In reality, if a 160 foot dinosaur was encased in ice, it would take hours or possibly days for the ice to melt if exposed to heat. Not ten seconds.