I have long hair which I air dry 95% of the time, even in winter (I work from home). Not because it's better for it, but because I'm lazy.
However I do use my GHDs on it once a month or so. I know this is not often compared to many people (especially because many people blow dry their hair) but I am curious as to how often people use heat on average. And, if you do, do you apply a protector first?