FlatironDoctors are catching on to what curlyheads have known for years: Flat irons are damaging to the hair.

Doctors are warning people about potential damage that can be done to one's hair by using a ceramic hair straightener at too hot a temperature.

Ceramic flat irons have become popular because the devices are effective at converting wavy or curly hair to sleek, shimmering locks.

According to a new warning from the American Academy of Dermatology, ceramic flat irons is used at too high a setting — some can reach up to 400 degrees — can change the molecular structure of a person's hair.

Dermatologist Dr. Bernard Nusbaum said, "The problem is using it way too frequently at too hot of a setting. Then what happens is women come in with hair breakage. The hair gets shorter and shabby."

Carolina Restrepo confessed she regularly uses her flat iron.

"I'm obsessed with straight hair. I iron it every other day," said Restrepo, who admitted she set the iron on the highest setting.

Restrepo works at Nusbaum's medical practice, where Nusbaum and Dr. Bernard Cohen developed a device that measures hair breakage.

They tested Restrepo's hair and found about 30 percent of her hair had been damaged. In the average person, between 5 and 10 percent of follicles are damaged.

There is good news for flat iron users. Nusbaum said a person's hair will grow back, and it is unnecessary to give up flat ironing completely.

Just turn down the heat, Nusbaum said, to no higher than 347 degrees. Also avoid using on wet hair and use a styling product that protects hair against heat, and limit flat iron usage to two to three times per week.

"The hair, when it is wet, is more susceptible to damage," Nusbaum said. "So do not use it on wet hair. Make sure the hair is dry."

Source: NBC10.com