Why will the roots process lighter during a hair treatment?

During a hair treatment, particularly in the context of lightening treatments such as highlights or full bleaching, body heat plays a significant role in the chemical process. The warmth generated by the scalp and hair can enhance the effectiveness of the lightening products applied to the hair.

When heat is present, it increases the activity of the oxidizing agents in the lightening solution, allowing them to penetrate the hair shaft more effectively and perform their action on the melanin (the pigment in hair). This can lead to a more efficient and sometimes quicker lightening process.

Therefore, body heat facilitates the reaction necessary for lightening the hair, leading to a more pronounced effect at the roots, which are typically the warmest part of the scalp. The other factors, while potentially impactful in different contexts (like product quality affecting overall outcomes or humidity affecting product performance), do not play as direct a role in enhancing the lightening process due to the body's natural heat.