This is one of the water bottles we used when we took a guided tour through the Yucatan Peninsula. We selected the option that did not include having chilled bottles of water in a cooler in the van for the princely sum of an extra $100 a day. We thought that we could manage our own water and then have extra money for food, excursions, souvenirs, etc. So I searched and found these water bottles that included a zippered insulated sleeve. We could "undress" the bottle, fill it with free bottled water from the hotel, freeze it overnight, and then in the morning "dress" the bottle in the insulated sleeve. The also had nice shoulders straps in case your backpack was too full.
When we reached our first, somewhat rustic hotel, I discovered that there was no fridge in the room and the bottled water was $7.00 US for a small bottle. I may have miscalculated this badly. It may be that away from the major resorts, bottled water is rare and expensive. After supper, we went out to the town and found that the little bodegas sold bottled water for prices much cheaper than even at home. We stocked up, and although we couldn't keep it very cold it was fine for our needs.