Which hair type is most susceptible to damage from heat styling?

Fine hair is the most susceptible to damage from heat styling due to its thinner structure and lower density compared to other hair types. Because fine hair has less protein and fewer cuticle layers, it is more vulnerable to the high temperatures of styling tools, such as flat irons and curling wands. This vulnerability can lead to issues such as brittleness, split ends, and overall weakening of the hair shaft.

In contrast, other hair types like coarse, curly, and thick hair tend to have stronger structures and can often withstand heat better. Coarse hair, for example, has a thicker diameter and more cuticle layers, making it more resilient to heat. Similarly, while curly hair might frizz or lose definition with excessive heat, its structural complexity can provide some natural protection against damage. Thick hair can also resist heat better because it has a larger mass, which allows it to distribute heat more evenly and take longer to reach damaging temperatures.