The Harvard Medical School found that one-third of American workers aren't sleeping enough. A lack of sleep translates to “presenteeism:” workers showing up for their jobs but operating at sub-par levels and costing their companies billions of dollars in lost productivity.

An estimated 40.6 million American workers—30 percent of the civilian workforce—don't get enough rest to function at their highest levels. Harvard experts estimated sleep deprivation cost U.S. companies $63.2 billion in lost productivity in 2011. For every hour of lost sleep, an employee wastes 8.4 more minutes online. A lack of sleep is especially dangerous in fields requiring overnight shifts such as manufacturing and healthcare. Severe exhaustion can lead to errors in the workplace that may cause injury.

Motivating a chronically exhausted workforce can be a struggle for those in management positions, who may often be experiencing their own sleep problems. Solutions include investing in sleep-hygiene courses or regulating workplace lighting. During peak business seasons where extended hours are occasionally required to meet deadlines or deliver a product to a demanding client, it may be beneficial to observe employee behavior and offer breaks to those who seem overworked or overtired.