I carry two cases, hard to call shrink wrapped package a case, in the truck. I go through an average of six bottles a day, but days like this week ... Don't have my truck this week, so no water right now, but I bought six one liter bottles through the day and haven't peed since I got up at 6:30. Heat and humidity suck, then throw in going in and out of a 22 f box all day, and in and out of 34f boxes on the other end of the run, all while lumping boxes that weigh from 45lbs to 95lbs, and your body becomes a giant puddle.