Describe how hair responds to cold Temperature or strong emotion?

In cold temperatures or during strong emotions, such as fear or excitement, hair can respond by standing on end due to the contraction of tiny muscles at the base of each hair follicle, a reaction known as piloerection. This physiological response is part of the body's fight-or-flight mechanism, which helps to create an insulating layer of air for warmth or make the individual appear larger to potential threats. Additionally, in cold conditions, hair may also become frizzier or drier due to reduced humidity, as the scalp produces less oil.