This study investigates the effects of ceramic and polymer heating plates on the surface and structure of hair. To evaluate the degree of hair damage caused by the iron and polymer heating plate materials, hair moisture content and the degree of hair fading were measured using Thermo Gravimetric Analysis (TGA) and a colorimeter, respectively. Additionally, a Scanning Electron Microscope (SEM) was used to analyze the change in the microstructure of the hair. As a result, hair treated using a polymer iron contained significantly higher moisture than hair treated using a ceramic iron. The colorimeter analysis showed that ceramic irons caused fading and damage to hair color, whereas polymer irons did not. Lastly, hair treated with a ceramic flat iron had extensive surface scratches and cuticle melting from the SEM analysis, unlike hair treated with a polymer iron, which preserves superior hair shape and cuticle integrity.