<P> While humans have developed clothing and other means of keeping warm , the hair found on the head serves as primary sources of heat insulation and cooling ( when sweat evaporates from soaked hair ) as well as protection from ultra-violet radiation exposure . The function of hair in other locations is debated . Hats and coats are still required while doing outdoor activities in cold weather to prevent frostbite and hypothermia , but the hair on the human body does help to keep the internal temperature regulated . When the body is too cold , the arrector pili muscles found attached to hair follicles stand up , causing the hair in these follicles to do the same . These hairs then form a heat - trapping layer above the epidermis . This process is formally called piloerection , derived from the Latin words ' pilus ' ( ' hair ' ) and ' erectio ' ( ' rising up ' ) , but is more commonly known as ' having goose bumps ' in English . This is more effective in other mammals whose fur fluffs up to create air pockets between hairs that insulate the body from the cold . The opposite actions occur when the body is too warm ; the arrector muscles make the hair lie flat on the skin which allows heat to leave . </P>
<P> While humans have developed clothing and other means of keeping warm , the hair found on the head serves as primary sources of heat insulation and cooling ( when sweat evaporates from soaked hair ) as well as protection from ultra-violet radiation exposure . The function of hair in other locations is debated . Hats and coats are still required while doing outdoor activities in cold weather to prevent frostbite and hypothermia , but the hair on the human body does help to keep the internal temperature regulated . When the body is too cold , the arrector pili muscles found attached to hair follicles stand up , causing the hair in these follicles to do the same . These hairs then form a heat - trapping layer above the epidermis . This process is formally called piloerection , derived from the Latin words ' pilus ' ( ' hair ' ) and ' erectio ' ( ' rising up ' ) , but is more commonly known as ' having goose bumps ' in English . This is more effective in other mammals whose fur fluffs up to create air pockets between hairs that insulate the body from the cold . The opposite actions occur when the body is too warm ; the arrector muscles make the hair lie flat on the skin which allows heat to leave . </P>
what is the purpose of hair on your head
what is the purpose of hair on your head
heat insulation cooling ( when sweat evaporates from soaked hair ) protection from ultra-violet radiation exposure
heat insulation cooling ( when sweat evaporates from soaked hair ) protection from ultra-violet radiation exposure