Flat irons, in particular, deliver intense heat directly to the hair shaft. One way to prevent damage when using a flat iron on your hair is to always be sure the hair is 100% dry before you start ironing it. Otherwise, any excess moisture left in the hair could literally boil. Water boils at 212°F, and most flat irons get far hotter than that—over 350°F is typical. What happens when that kind of heat comes in direct contact with the hair, especially if you leave it in one place for too long, is that the water inside the hair shaft boils and turns to steam, which causes the hair to break or rupture at every boiling point. But all that has changed with a new generation of flat iron that can be used on hair whether it is wet or dry. A special venting system built into the plates of the flat iron allows the steam to escape instead of remaining in the hair shaft, thus eliminating the damage and creating straight smooth hair as the hair dries.
You will find that a wet to dry flat iron will work best on damp hair, as opposed to hair that is soaking wet. Dripping wet hair can take a long time to dry and smooth. Removing some of the moisture first with a blow dryer will make things go a lot faster. Wet/dry flat irons are also great for touch-ups on mornings when you aren’t going to wash your hair. A stubborn area can be sprayed with water and easily and quickly restyled.