To properly rinse a lightener from hair, the water temperature should be?

Using tepid water to rinse a lightener from hair is beneficial because it provides a balanced temperature that is comfortable for the scalp while still effectively removing the product. Tepid water helps to close the hair cuticles slightly after the lightening process, allowing for better maintenance of the hair’s integrity and preventing excessive swelling of the hair fibers that can occur with hotter water.

Hot water can strip the hair of moisture and may exacerbate any potential damage caused by the lightening process, while cold water may not effectively wash away the chemical lightener, leading to a residue that could negatively affect the hair afterwards. Tepid water strikes the right balance, ensuring that the rinse is both effective and gentle on the hair and scalp.