The "hot modulus" fields shouldn't be disabled, what Version of CAESAR II are you using?

If you want to use the "hot modulus" for equipment nozzles, the easiest thing to do is setup duplicate load cases, and for these cases go to the "Load Case Options Tab" and (a) select which hot modulus to use, and (b)in the output type, pick "displacement/force" - which means there won't be stresses available for these load cases.