I have recently changed my hairstyle and have been using my hairdryer a lot more to get my hair straight. My hair is fine, with some natural waviness/cowlicks, so I straighten it every second day using a round brush and hairdryer. In the last few weeks, I have noticed that my hair won't seem to stay straight no matter how long I dry it for, or how hot the hairdryer is set. My hair goes frizzy and springs into waves about 20 minutes after I've finished styling. I haven't changed any of the products I use, so I'm wondering if I've caused heat damage to my hair, and whether this is responsible for increased tendency to frizz. Or perhaps it's just a change in the weather? Does heat damage make hair to harder to control?