The reaction of the skin to cold or fear. The blood vessels contract and the small muscle attached to the base of each hair follicle also contracts, causing the hairs to stand up: this gives the skin an appearance of plucked goose skin.
Skin where hair follicles become notably visible due to the contraction of tiny muscles known as arrectores pilorum. This muscle contraction is commonly triggered by cold temperatures but can also be caused by fear. Also referred to as horripilation.