i would think that instead of being in imminent physical danger, although that is possible, he is at a far far greater risk of being in a delerious sleep-walking state of blackout, and will do something harmful to himself or others, possibly end up with criminal charges/be put in a psych ward. don't leave him alone. dont let him take any more drugs of any kind. if he sleeps pay attention to his breathing. first hint of trouble be ready to call 911.