How are you falling in love? Just by working together on a project, talking technical things, working in close proximity and having normal office talk? If that is so, it is just an attraction, crush or fantasy of possible love. How do you know that the same feelings will remain if you get to know him intimately?
Just the fact that it is unattainable and dangerous makes you feel anxious & afraid (which causes faster heart-beat). SInce the possibilities are end-less in the fantasy world you can not stop thinking how beautiful things can be.
You are also probably a studious person with hardly any social life. So, this one boy at close proximity makes you feel as if he is one and the only and the most wonderful person in the world. Has he done anything special for you?
So, my suggestion is: GET A LIFE! Go out more. Meet other people. Do other interesting things. Then this question will become redundant.
Of course, if you are afraid of losing this feeling (because you seem to enjoy this som much) do not do anything and live in this fantasy world.