This piece originally appeared on the SHRM Blog. Its author, Paul Wolfe, is SVP of Human Resources at Indeed. He oversees all global human resource functions, including talent acquisition, employee retention, compensation, benefits, and employee development.

Many of us Americans don’t know how to take true summer breaks.

59% of Americans Didn’t Take A Summer Break in 2016

When you work at a global company, you likely know this anecdotally. You notice that colleagues based in cities ranging from Toronto to Berlin take at least two weeks, and sometimes a month. They also holiday at other times of they year, such as significant holidays.

And when they say they’re on vacation, they mean it. They’re not checking emails. They’re not answering calls. They’re not fiddling in shared documents or meeting clients.

Meanwhile, if you’re a U.S. worker, did you really take vacation this summer? Meaning, did you tune out from work completely and reset as much as possible during the days you had off?

Toward the end of summer, we surveyed about 2,000 full-time working adults in the U.S. It turns out that a surprising 20 percent of those surveyed took no summer vacation, and perhaps more startling, 59 percent of those who did take time off did some form of work while on break.

We all know, in theory, that taking a break is important to recharge our batteries. So why don’t we do it?

I suspect a lot of it is because of self-created fears that taking vacation will be detrimental to our careers. We’re worried that if we’re not there the boss, or colleagues, will suddenly start thinking we’re not needed. Or, if we’re aiming for a promotion or some kind or raise–which many good workers often are–that taking a vacation will put us back in our goals.

Before seeing the survey results, my hunch would tell me that paranoia is making most people work on vacation, and that it’s an unnecessary fear. Not only is it fine for a good employee to take time off, but in fact, if they are unable to leave work alone it should be a red flag. A manager might wonder: why haven’t they learned to delegate? Why don’t they trust their colleagues to cover for them?

I was surprised, however, to see that 57 percent of respondents in our survey reported some degree of difficulty taking vacation due to work culture. That may be due to this same self-inflicted perception, but it does indicate some offices in the U.S. are not getting it right when it comes to time off.

If employees don’t feel their workplaces encourage vacation, managers and HR leaders should take heed of the problem.

For one, it’s simply not acceptable to expect your employees to work nonstop all year round. We all want committed and loyal employees who believe in what they do. But we also want well-rounded people who have lives outside of work.

Second, employees who don’t get time off will burn out. In America, we thrive on the idea that we have incredible endurance and can tackle any task. This is not a bad thing. But we also need to realize that we need to recharge, and in fact, some solid rest and relaxation will help us be at our best when we return.

HR teams can foster this kind of culture in a few ways. In my role at Indeed, I try to do the following:

• Institute policies that make time off a priority. This year, we instituted unlimited paid-time-off. We don’t want to nickle-and-dime employees with their time off. Rather, we want to give them a chance to work out the best schedules with their managers to make both work and life enjoyable.

• Celebrate life outside of work. A great work culture allows for people to have great lives. Foster an environment where extra-curricular activities, whether it’s scaling Mt. Everest or hosting a child’s birthday party, is celebrated and discussed.

• Lead by example. Senior leadership should make a point to take time off. Let direct reporters know you’re going away and what the chain of command will be in case of emergencies. If the President of the United States can take vacation, so can a CEO, president, or department head. If you find you literally can’t step away, there is a problem with your management chain that may lead to bigger problems than just time off.

One a final note: for the 20 percent who did not take any summer vacation, the holidays are around the corner. Take some time off! You, and your company, will be better for it.