I'd like to add one potentially serious emergency that I mentioned in Phat's new thread. That's when you keep on vomiting/having diarrhea that doesn't stop. No matter how much water you drink, a goodly portion of it will exit from one end or the other before your body can absorb it. You will quickly become dehydrated to a dangerous level. My youngest son had this happen on a weekend outing--after a couple days of this he ended up being hospitalized for three days. In this case you need to seek help or push the PLB button immediately.