Experts believe they have finally uncovered the secret to a good night's sleep.
And stressed workaholics have been told to banish their mobile phone, Blackberry and laptop computer from the bedroom for at least an hour before they go to bed.
Dr Chris Idzikowski, of the Edinburgh Sleep Centre, said: "Checking your work emails before bed on any electronic device is essentially the equivalent to drinking a double espresso last thing at night.
"Research has shown that light from a laptop or Blackberry is concentrated enough to signal your brain to stop production of melatonin, a natural hormone known to aid sleep disturbances.
"Being in a relaxed environment and incorporating essential wind-down time into your day is your best chance of securing a great night's sleep – along with silence, darkness and comfort."
Work-related stress is one of the major factors when it comes to not being able to sleep at night, with the average Briton suffering an estimated 55 nights of poor quality sleep a year.