I know it's both a cliché and something that westerners often have forgotten how to do, but you can actually listen to your body and know minute by minute if you're in danger or not. For dry fasting, you are told that if you start getting persistent high heart rate you should stop.
Now what you should find intriguing is why would anyone put themselves through this? Well, it has immense and unique health benefits, that's why. It's been studied, although less than water fasting for obvious reasons. Even water fasters think we're crazy, so I understand.
