What is the difference between cold wave and hot wave perms?

The correct answer highlights that cold wave perms use thioglycolate as a chemical agent for the perming process, while hot wave perms utilize heat to enhance the treatment. Cold wave perms, also known as alkaline perms, activate with room temperature and rely on thioglycolic acid or its derivatives to break the disulfide bonds in the hair. This method is suitable for creating softer curls and is typically less damaging to the hair.

In contrast, hot wave perms, also referred to as exothermic perms, use a heat source, which may come from the chemical reaction itself or from external heat sources. The heat helps to speed up the chemical process of breaking and re-forming the disulfide bonds, resulting in stronger curls.

The distinction between these two types of perms is crucial for cosmetology professionals as it informs their choice depending on the hair type and desired results. Knowing which method to apply can influence the outcome of the perm and the health of the client's hair.