© Herbal Essences
Around 30% of women have curly hair, natural or otherwise.
The first ever perm (chemical + heat treatments) was carried out at the beginning of the 20th century by a hairdresser of German origin.
Curling techniques have evolved greatly since then: in the 1930s heat-free perms first came about, and in 1940 cold perms were developed. Nowadays perms are normally carried out at room temperature.
As far as home curling accessories go, the first irons came out in 1900, while heated curlers first made their appearance in the 1930, and in 1980, curling tongs came onto the market.
Digital technology is the next big thing in curling. For maximum speed and effectiveness, you can control the temperature and time yourself according to your needs and the look you're trying to achieve.