Using an iron two times in one day?

I messed up my hair a few hours ago when I was curling it with my flat iron. How safe is it to take a shower, dry my hair, and do it over (2x in one day?). I know using an iron even ONCE a day is terrible for your hair but I really messed up my hair?Using an iron two times in one day?
It isn't the iron! Blow drying your hair takes 90% of the moisture out of it and is the real damage component, the flat iron just takes the wrap for it for some reason. If you use a heat protectant or thermal styling spray and condition your hair with salon shampoo you will be fine.