If you have ever not known when you are thirsty that may be a problem now, but in the future thanks to the researchers at Cambridge have come up with a way for your water bottle to tell you when you are thirsty. This works by the bottle itself measuring how much water you have consumed, your heart rate via a small cord attached to your chest, and an app on your smartphone. This idea is not out of the concept stages yet, but they will be showcasing the idea at CES in a few weeks. In that time we will see if the I-dration fitness bottle is really the future of water bottles or not.