I wonder ...

What stimulates the growth of hair in humans? Specifically is hair growth stimulated as a response to our bodies need to keep warm over a prolonged period of time? Why this odd question? Unlike Prince Phillip, I have no problems growing natural fibers i.e I am naturally a hairy so I am used to seeing hair in really odd places. This morning as I was getting dressed I noticed hair all over my chest (from my the top of my boobs up), hair that I know for sure I hadn't seen before. This wasn't the 'normal' chest hair, (wiry/curly) its the downy kind of hair, you know the kind that women/pubescent boys grow on their upper lips? There are two possible answers to the question 'Am I turning into a werewolf?'; 1. The hair had always been there, I had just grown fairer and it was now more noticable or 2. As a response to my always feeling cold, my body had received an emergency work order to produce these fibres to trap the heat my body produces naturally and keep me warm. I don't think its the former, (I am rubbing my body with Palmers Cocoa Butter not know for its skin lightening qualities) and the latter sounds really evolutionish although the human body is just awesome just like its designer/architect. Anyone with a probable answer? anyone?