With the summer season coming to a close, some workforces are planning to reopen their offices this fall. But, as employees prepare to return to the office, almost half say they’re worried about possible COVID-19 exposure.

A new study conducted by The Conference Board in August found 42% of the 2,400 workers surveyed are worried about returning to the workplace for fear of contracting the Delta variant of the coronavirus. That number has increased by almost 20 percentage points, compared with 24% who had the same concern in June.

“With headlines about the rise of the Delta variant, breakthrough cases among the vaccinated and an overburdened health care system in much of the country, COVID-19 concerns that were subsiding just two months ago have risen,” says Rebecca Ray, executive vice president of human capital at The Conference Board.

Younger employees were more likely than other generations to be more concerned about COVID-19 exposure, job security and mental health. More than half (53%) of Millennials surveyed said they were concerned about contracting COVID-19, compared with 41% of Generation X respondents and 45% of Baby Boomers surveyed.

Similarly, 61% of Millennials said they were worried about exposing family members to COVID-19, while 42% of Gen Xers and 40% of Baby Boomers said they had the same worries. Millennials were also more likely to feel pressure in returning to the workplace to keep their jobs (30% vs. 21% of Gen Xers and 19% of Baby Boomers) and, as a result, faced worries about their mental health deteriorating (38% vs. 21% of Gen Xers and 16% of Baby Boomers).

Survey findings also revealed that one-third of workers are considering leaving their jobs within the next six months, with many hoping to find flexible work environments. However, 63% indicate no plans to leave within that time frame.

More workers are also increasingly saying they enjoy benefits of flexible work arrangements. Eighty percent of workers said such arrangements are “very important” or “important” in their decisions to leave their current job, and respondents ranked flexible work locations as the most desired aspect of a new job, even prioritizing it over better pay and career advancement.

In fact, workers—especially women (42%) and Millennials (48%)—are questioning the wisdom of returning to the workplace, given their belief that productivity remained high while working remotely, according to the study.

“The long-term effect of extended remote working arrangements has left its mark. Employees are much less willing to embrace the rigid, conventional work policies of the past about how and where work gets done,” Ray says. “Especially for women, to whom the bulk of caretaking and household responsibilities still unfortunately fall, the flexibility to choose what works best for them is critically important. We are starting to see companies with flexible work arrangements successfully attracting the top talent of their competitors who have adopted a more rigid stance. The challenge of attracting and retaining talent in a tightening labor market is only going to become more difficult.”

Therefore, she says, traveling to an office full-time may be a thing of the past, as most workers say they prefer hybrid work arrangements. Sixty-seven percent of respondents said they would be willing to work a hybrid work schedule (i.e., split time working in the workplace and at home), while 20% said they only want to work remotely. Only 4% said they want to work entirely in the office.

While an overwhelmingly number of respondents long for hybrid and remote options, the study warns that this may come at a cost for some employees. Top employee concerns over remote work environments included a lack of boundaries between work and life; working more hours; a shortage of visibility and exposure that could impede upward mobility; and increased isolation.

The survey also says some workers have also become less engaged with their work over time, whether that’s due to working remotely and/or working in a pandemic. Compared with pre-pandemic levels, fewer respondents reported that their engagement levels had increased. Thirty-seven percent of respondents said their engagement level had increased back in June, but in August, that number dropped to 30%. Roughly half of respondents said their engagement now is the same as it was pre-pandemic.