There were reports this week that Prince was up for 154 hours straight before his death last Thursday. Whether sleeplessness contributed to his demise or not, it’s bad for you and it’s bad for your employer.

In several recent studies, U.S. workers reported that sleepiness is impacting their performance at work. It doesn’t take a huge leap of faith to know that this hurts employers as well.

A CareerBuilders survey of 3,200 U.S. workers found that just 16% of those responding said they get the recommended eight hours of shut-eye per night. Most (63%) logged between six and seven hours per night during the week, while 21% admitted they average less than five hours.

The reverberations are felt in the workplace, where nearly half of the respondents (43%) said they have “caught” someone else sleeping at work. No wonder nearly that number (39%) said they would likely use a nap room if one were offered.

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Another survey of 1,000 U.S. workers by Robert Half’s (RHI) Accountemps unit came up with similar findings—that 74% of those responding said they work while tired. More than half (52%) reported that this leads to a lack of focus and distractedness; and (shocker!) 38% said their fatique makes them grumpy. Oh, and 55% said they’d use a business-provided nap room.

One of the biggest issues is that tired people can call in sick to rest or, perhaps worse, show up to work too tired to do a good job. Nearly a third of those surveyed by Accountemps said their sleepy states led them to make more mistakes than if they were well rested.

In an interview with NPR, Accountemps vice president Bill Driscoll cited a few examples in which tired (unnamed) accountants admitted big snafus. One accidentally deleted a project that took 1,000 hours to put together while another missed an errant decimal point, which resulted in $1 million overcharge.

Still, another employee surveyed admitted to mistakenly reformatting a server.

How to fit sleep into your busy schedule. Watch:

It’s hard to quantify how much all this sleepiness costs businesses in aggregate. But as a marker, Harvard Medical School researchers estimated five years ago that, at that point, sleepy workers were costing U.S. businesses $63.2 billion in lost productivity per year.

Most of that loss was due to what researchers called “presenteeism,” a term that describes people coming to work despite being overly tired and not able to perform well.

Some employers are taking all these stats to heart. Insurance giant Aetna (AET), for example, is providing cash incentives to encourage employees to rest up, according to Stat News and other outlets.

Workers who get at least seven hours of sleep for 20 consecutive nights can earn $25, with the total amount capped at $300 per year. If they meet other “wellness” goals, they can earn up to $500 per year. The sleep data can be provided via a Fitbit device or entered manually.

In an interview with CNBC, Aetna chief executive Mark Bertolini said the company has seen a 69-minute-per-month boost in employee productivity, which he attributes to the company’s focus on wellness, a big component of which is rest.

So, listen to Arianna, if not for yourself, then for your company. Get some sleep.

Note: This story was updated at 5:30 p.m. EDT with the Prince reference, which, frankly was supposed to be in the story from the beginning, but sleepiness also begets forgetfulness.