I have had a couple of drives die on me in the first year. And I have a few drives that are approaching 20 that are still working (though another one did die a year or two ago). You don’t know when a drive is going to die, only that nothing lasts forever, so that’s why to have backups.
These are all drives that were plugged in and constantly on. For drives in cold storage, I would be even more nervous about whether the drive would successfully power back on after years of being off.
I’ve run more than that in a small closet with poor ventilation. Only got up to around 85 F or so. Unless your room is super duper sealed, you probably don’t need to do anything special.