What is a potential consequence of excessive heat on hair?

Excessive heat can indeed lead to dryness in hair, which is a significant consequence of overexposure to heat styling tools such as blow dryers, curling irons, and flat irons. When hair is subjected to high temperatures, the moisture content within the hair can evaporate, resulting in a lack of hydration. This dryness can make the hair more brittle and susceptible to damage.

As the hair loses its natural moisture, the cuticle, which is the outer protective layer, can become rough and less effective at protecting the inner structures. This condition ultimately leads to split ends, as the weakened hair is more likely to fray and split at the ends. Therefore, the statement that excessive heat can cause dryness and lead to split ends accurately describes one of the critical risks associated with using heat on hair.

In contrast, the other potential outcomes mentioned—such as increased shine, smoothness, curls and bounce, or strengthening the hair shaft—do not hold true in the context of excessive heat application, as they are typically benefits of heat when used in moderation rather than a consequence of excessive exposure.