I'd definitely approach this with caution. I do think conventional wisdom overplays hydration, and sipping water all day is clearly not necessary (the analogy I have heard many times is that cavemen didn't carry water bottles). But I am ignorant to the benefits of going a day without water, unlike the well-documented benefits of food fasting, plus, I see no reason to disbelieve the medical establishment when they state how quickly you can die or suffer serious harm without water (as opposed to food which you can abstain from for long periods). If you really have to try it, I'd definitely observe yourself carefully and stop it if there were any ill effects. I also suspect doing it in the heat of the summer is probably not adviseableadvisable!

I'd definitely approach this with caution. I do think conventional wisdom overplays hydration, and sipping water all day is clearly not necessary (the analogy I have heard many times is that cavemen didn't carry water bottles). But I am ignorant to the benefits of going a day without water, unlike the well-documented benefits of food fasting, plus, I see no reason to disbelieve the medical establishment when they state how quickly you can die or suffer serious harm without water (as opposed to food which you can abstain from for long periods). If you really have to try it, I'd definitely observe yourself carefully and stop it if there were any ill effects. I also suspect doing it in the heat of the summer is probably not adviseable!