system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How is it that when women apply heat to their hair it becomes softer and shinier, but is actually damaging the hair?
gpt
When hair is heated the proteins that make up hair (keratin) are damaged (denatured). In doing so they don't hold together as well. This makes the hair softer.  In essence, damaging the hair through heat is what causes the hair to be softer. Not sure what causes the shininess though.