A handheld tool attaches hair extensions. The tool has two hand members. The members are mechanically coupled to each other and moveable with respect to each other. The tool includes a fastening mechanism. The fastening mechanism is configured to crimp a pliable material to form a fastener that attaches the hair extension to the recipient's hair. The tool includes a shield mechanism, which is coupled to one hand member. The shield mechanism includes safety feet having first and second positions. The shield mechanism is in the first position when the apparatus is in a quiescent position, and the shield mechanism is in a second position when the fastening mechanism is crimping the fastener. In the second position, the feet are interposed between the recipient's scalp and a cornrow of the recipient's hair. The safety feet move from the first position to the second position as the fastener is being crimped.