You may think you’re wowing your boss by burning the midnight oil, but putting off a good night’s rest could be having an adverse effect at work or school. In fact, sleep has been linked to improved concentration and higher cognitive function, both of which can help you be successful at work. But one restless night can leave you feeling frazzled, making it more likely that you’ll make mistakes that a pot of coffee won’t be able to fix. Speaking of coffee, the more tired you feel, the more likely you are to reach for that afternoon cup. And while that may seem to fix the afternoon crash problem you experience, the extra caffeine late in the day could set you up for another sleepless night. Talk about a counterproductive cycle.