for me, i must eat before i smoke up.. if i havent eaten much in a day and i would get all pale, faintin n not feeling good. happened to me two times.. one of my friends, he usually doesnt eat much. after he smoked up in a hot day, he passed out. that has been happened to him twice. he broke his nose once.. so always eat before u get high! anyway it really all depends on how much u smoke.