First of all, the statement was: “In college I never use a calculator not even on homework. It’s best to get used to doing things by hand”
No qualification like “only lower-level classes.” No “except for heat transfer.” The claim was that it is best to do things by hand in college, even on engineering homework.
That is absolutely and completely untrue.
It’s not even always true at the freshman and sophomore level. My physics classes had homework on MasteringPhysics. You NEEDED a calculator for that. I took the honors versions of three math classes, which were more theoretical than the usual ones, and still used a calculator.