What is the type of hair that is short, fine, and downy, aiding in perspiration evaporation?

The type of hair that is short, fine, and downy, which plays a role in assisting the evaporation of perspiration, is vellus hair. This fine hair is less pigmented and shorter than other types of hair on the body. Vellus hair covers most of the human body and is particularly prominent in areas where thermal regulation and moisture loss are significant.

In contrast, lanugo hair is a type of fine, soft hair that is typically found on fetuses and is usually shed before or shortly after birth, making it less relevant to adult physiology. Terminal hair is thicker, longer, and more pigmented, commonly found on the scalp, face, and body during and after puberty. Guard hair refers to the coarse, longer hairs that provide protection and do not fulfill the same function related to perspiration evaporation. Thus, vellus hair serves its specific purpose effectively in this context.