Which hairstyling tools utilize heat for styling?

The correct choice identifies flat irons and curling irons as hairstyling tools that utilize heat for styling. These tools are specifically designed to apply high temperatures to the hair, enabling a variety of styles. Flat irons, for instance, are used to straighten hair by using heated plates that clamp down on the hair strands, while curling irons create curls or waves by wrapping sections of hair around a heated barrel. The application of heat alters the hair's structure temporarily, allowing for versatile styling options.

In contrast, hairbrushes and combs do not produce heat; they are primarily used for detangling, smoothing, and styling hair without any heat application. Hair rollers may be heated in some cases, but typically, they rely more on setting the hair in a specific shape through a combination of tension and, at times, the natural heat of the scalp rather than direct, high-temperature application like that of flat irons and curling irons.