Trying to save a plant!!!?

so this is a young plant... a friend just called me up tweaking... he said that they left the window open last night and the top of their plant (yea its pot) is all wilted and dead from the cold... dumbes.... but he wanted to know if you can cut the top of the plant off and the stem could still get enough light and nutrients to save it... i dont know because i dont know what jsut a stem of a plant will do if there are no leaves to help retain lighta nd nutrients and whatnot... any tips/advise etc would eb great!!!!! i know someone out there can tell me what he shold do... personally i feel as though it should be left alone to see what it does or its just fkked....