Final answer:
A stylist would use a keratin glue hot tool while styling a single braid with extensions to securely attach the extensions to the natural hair.
Step-by-step explanation:
A stylist would use a keratin glue hot tool while styling a single braid with extensions when they need to attach the extensions securely to the natural hair.
Keratin glue is a type of adhesive that is commonly used in hair extensions. It melts when heated and becomes sticky, allowing the stylist to bond the extension to the natural hair.
By using a hot tool, such as a hair straightener or a specially designed keratin glue applicator, the stylist can melt the keratin glue and apply it to the hair, creating a strong and durable bond between the extension and the natural hair.