HELP. some friends are coming over later and were going to be smokin, and one drinking...?

when he pes out what pre cautions should I take? he's a little guy hes probably no more then 130 to 150 pounds, shot, and hes planning on drinking absolute vodka. So as you can imagine he will get drunk of not too much alcohol. if he pes out what should i do to him to garuntee saffety? i dont think hes going to get black out drunk or anything. but should i try to limit his drinking? and should i flip him over while he's sleeping? if so how exactly should i