Unless you spend a lot of time in medical-state dispensaries, you probably haven't encountered the latest superstrong stoner craze: butane-extracted hash oil (BHO). How potent is it? A chunk of the stuff the size of a Tic Tac can be the equivalent of hoovering up an entire joint in one massive toke. Even for hardcore smokers, the experience – which fans call dabbing – can be like getting high for the very first time. Your head spins, your eyes get fluttery, a few beads of sweat surface on your forehead and, suddenly, you're cosmically baked.