Flat irons are brutal on hair, as is blowdrying.
I just think I have very sensitive hair that required gentle treatment. But then, all women should treat their hair gently!
Since your salon uses Matrix colors, next time see if they have a Matrix product called Vavoom Gold Heat (its a spray on, dry mist protector). It helps calm my hair down alot. (Its about $15.00 or so a bottle which last a couple months).