Temperature at which object reaches maximum physical stability

So a random thought crossed my mind, I am not sure if it makes sense at all. I apologize for the very amateur question: is there a name for the specific temperature at which an object reaches an optimum state and stability, i.e. is resistant to deforming?

For instance, an iron rod, if heated enough, will bend with ease and if near absolute zero will be fragile. What is the "optimal temperature"? I couldn’t find anything relevant on the web.