What is the function of the hair shaft?

Hair shafts have various functions, including regulating body temperature, protecting sensitive parts of the body from harm and facilitating the evaporation of sweat, according to Dartmouth University. Hair shafts are the visible part of hair on the surface of the skin.

Hair shafts protect the skin in a variety of ways. For example, the hair on the top of a person's head serves to protect the skull from excessive heat and cold. Hair shafts provide warnings in some instances. If an insect alights on a person's body, the individual often feels the presence of the insect due to the tingling of a hair shaft. Hair shafts in the form of eyelashes help to protect our eyes as well.