Camels can go many weeks without drinking anything at all. The notion that they cache water in their humps is pure myth—their humps are made of fat, and water is stored in their body tissues. While other mammals draw water from bloodstreams when faced with dehydration, leading to death by volume shock, camels tap the water in their tissues, keeping their blood volume stable. Though this reduces the camel’s bulk, they can lose up to a third of their body weight with no ill effects, which they can replace astonishingly quickly, as they are able to drink up to forty gallons in a single watering.” (pp.69-70)
We often give painkillers the credit that ought to be given to the passage of time, the belief that they would kill the pain, or the water that accompanied them.