YOU HAVE TO SLEEP AT THE RIGHT TIME. MINDY: IT IS VERY HARDWIRED. WE FOUND OUT THAT EVERYTHING SLEEPS AND EVERYTHING HAS A CIRCADIAN RHYTHM TOO. IT’S AN INTERNAL CLOCK. OUR BODIES ARE HARD-WIRED BY ...

New tests to gauge an individual's circadian rhythms could be put to good use helping night workers fend off the ill effects of their unsocial hours ...