According to the American Academy of Dermatologists, you should never set your flat iron to its highest heat. At their Summer Academy Meeting at the end of last month, dermatologist Paradi Mirmirani presented information on the potentially long-term damage caused by even the newest ceramic heat tools. Once you hear what actually happens to your strands when they come in contact with extreme heat, you might embrace your natural curls.
To find out, just read more.
The AAD says:
Temporary hair straightening using a flat iron is achieved by applying heated tongs to the length of the hair. This heat breaks and then reforms the hydrogen bonds in the inner core of the hair fiber. Dr. Mirmirani noted that while the goal of straightening is to alter the inner substance of the hair, the unwanted consequence may be damage to the outer protective cuticle, causing weathering, damage, and eventual hair breakage.
Hair weathering or damage is usually characterized by dry ends or flyaway hair. However, if breakage occurs, it can happen anywhere along the length of the hair and cause a shaggy or skimpy appearance to the hair. When this occurs, flat-iron users may use the device even more frequently to try to tame the broken or uneven appearance of their hair — which can lead to more damage.
What a vicious cycle! Mirmirani advises never to set the temperature above 347°F (175°C), or on low/medium and to use protective products. So while you don't need to give up all of your heat tools per se, at least be smart about the way you're using them.