What is the primary function of thermal protectants?

The primary function of thermal protectants is to shield hair from heat damage caused by styling tools. These products are specifically formulated to form a protective barrier around the hair strands, helping to prevent damage from the high temperatures generated by tools such as flat irons, curling wands, and blow dryers. When heat is applied to hair without adequate protection, it can lead to issues like dryness, split ends, and breakage. Thermal protectants often contain ingredients that can withstand high heat and can also help maintain the moisture content of the hair, allowing for healthier styling.

Other options relate to different purposes. Enhancing shine or providing moisture are important benefits of various hair care products but do not address heat protection specifically. Holding hairstyles in place is a function associated with styling products such as hairsprays or gels, which help maintain the shape and position of a style rather than protect against heat. Thus, the correct answer highlights the crucial role of thermal protectants in maintaining hair health during heat styling.