To keep the water cold, you need to put cold water in it to reach the desired temperature and then replace it with new cold water. This way, it comfortably keeps it for 12+ hours.

The problem it has, however, is a manufacturing issue because the lid at the drinking point retains a little water around it. Once you close the lid, this water can spill out if you turn it sideways or upside down.

I use it daily on my machine, the sun hits it and the liquid inside doesn't get affected at all! It fully maintains the temperature of the liquid!

I suggest reading the instructions (e.g., for hot beverages, it is good not to screw the lid tightly with the liquid), and waiting for it to reach the temperature indicated in the instructions (where it can also be consumed).