Researchers at the University of Chicago (in the ‘80s) wanted to find out what happens when animals (rats) are deprived of sleep for a long period of time. As the rats went longer and longer without sleep, their bodies began to develop strange spots and festering sores that didn't heal, their fur started to fall out in large clumps, and they lost weight no matter how much food they ate. So the researchers decided to perform autopsies, and lo and behold they found nothing wrong with the animals' organs that would lead them to failing so suddenly. This mystery gnawed at scientists so much that twenty years later, another team decided to do the exact same experiment, but with better instruments. This time, they thought, they will find out what happens inside of a rat's body during sleep deprivation that ultimately leads to its death. Again the rats stayed awake for more than two weeks, and again they died after developing gnarly sores. But just like their peers in Chicago years earlier, the scientists could find no clear reason for the rats’ demise. The lack of sleep itself looked to be the killer. Their conclusion was that staying awake for so long drained the animal, causing it to lose the ability to regulate its body temperature. More tomorrow.