Does leaving the window open affect whether i throw off a cold or not? on day one, i felt slightly sick like i was coming down with something. but after getting a good night's sleep, i felt better on day two. however, that night i left the window open and

Thats : Thats very difficult to determine. The cold air does not cause a cold, usually a common virus does that. However the cold air from thew window may have weakened your immune system, which left you ill equipped to fight off the looming cold; so to answer your question, if you had not left the window open then there is a good chance you probably would not have gotten sick.