Millions of American workers are suffering from economic whiplash, thinking they were finally returning to work only to be sent home again because of the coronavirus’s latest surge. Stores, restaurants, gyms and other businesses that reopened weeks ago are shuttering once more, and this time Congress appears less inclined to provide additional aid. Other companies that had banked on customers returning and restrictions lifting — such as hotel chains, construction firms and movie theaters — are seeing hours cut and reopening dates pushed back indefinitely as consumer demand stalls.

And many governors, including some who had drawn scrutiny for initially playing down the virus’s risks, are issuing new safety restrictions, in some cases just weeks after the first round of guidelines had begun to lift. In recent weeks, three states — California, Florida and Texas — have implemented new policies that partly restrict restaurant or bar service. Nine others — Arkansas, Delaware, Idaho, Louisiana, Michigan, Nevada, New Jersey, New Mexico and North Carolina — have postponed or slowed reopening plans.

Thousands of workers are caught in these rapidly shifting seas, many of them hourly and low-wage service employees, and are now facing unemployment for a second time. They say the past few months have been jarring: navigating unemployment in March, preparing to go back to work in April or May, and now confronting the prospect of another long stretch without a paycheck.