In Texas, more than 143,300 cases of Covid-19 have been reported, with 2,366 deaths across the state, according to the Texas Department of State Health Services. Gov. Greg Abbott has called the rate of spread unacceptable, saying "it must be corralled." Last week, he hit pause on the next phase of the state's reopening, and ordered bars to close and restaurants to reduce seating capacity.

"Closing down Texas again will always be the last option," Gov. Abbott said.

Peter Hotez, dean for the National School of Tropical Medicine at Baylor College of Medicine in Houston, said companies and civic leaders should delay reopenings and keep workers at home until cases trend down. "If these numbers continue to accelerate at this rate, then we could basically be looking at Houston becoming the worst-affected city in the U.S.," he says.

Most companies are acting more conservatively than the government.

Dell Technologies Inc., based outside of Austin with 165,000 global employees, estimates only 50% of its workers will ever go back to an office, even when the crisis passes. The company built its own digital tool to analyze more than a dozen data points, such as local cases and hospitalizations, to guide its decision.

"When the data tells us it's safe to return, we'll return," says John Scimone, a senior vice president and chief security officer at Dell.

That appears to be far off. "We are telling people that they need to settle in," says Jennifer "JJ" Davis, senior vice president of global communications. "We are predicting within our company and, frankly, more broadly, that the future of work looks different and that more people will stay home permanently."

Write to Collin Eaton at collin.eaton@wsj.com and Chip Cutter at chip.cutter@wsj.com