This is a command center in Foster City, Calif., operated by Zoox, a self-driving car company owned by Amazon. Like other robot taxis, the company’s self-driving cars sometimes struggle to drive themselves, so they get help from human technicians sitting in a room about 500 miles away.

Inside companies like Zoox, this kind of human assistance is taken for granted. Outside such companies, few realize that autonomous vehicles are not completely autonomous.

For years, companies avoided mentioning the remote assistance provided to their self-driving cars. The illusion of complete autonomy helped to draw attention to their technology and encourage venture capitalists to invest the billions of dollars needed to build increasingly effective autonomous vehicles.

“There is a ‘Wizard of Oz’ flavor to this,” said Gary Marcus, an entrepreneur and a professor emeritus of psychology and neural science at New York University who specializes in A.I. and autonomous machines.

If a Zoox robot taxi encounters a construction zone it has not seen before, for instance, a technician in the command center will receive an alert — a short message in a small, colored window on the side of the technician’s computer screen. Then, using the computer mouse to draw a line across the screen, the technician can send the car a new route to follow around the construction zone.

“We are not in full control of the vehicle,” said Marc Jennings, 35, a Zoox remote technician. “We are providing guidance.”

As companies like Waymo, owned by Google’s parent company, Alphabet, and Cruise, owned by General Motors, have begun to remove drivers from their cars, scrutiny of their operations has increased. After a series of high-profile accidents, they have started to acknowledge that the cars require human assistance.

While Zoox and other companies have started to reveal how humans intervene to help driverless cars, none of the companies have disclosed how many remote-assistance technicians they employ or how much it all costs. Zoox’s command center holds about three dozen people who oversee what appears to be a small number of driverless cars — two in Foster City and several more in Las Vegas — as well as a fleet of about 200 test cars that each still have a driver behind the steering wheel.

When regulators last year ordered Cruise to shut down its fleet of 400 robot taxis in San Francisco after a woman was dragged under one of its driverless vehicles, the cars were supported by about 1.5 workers per vehicle, including remote assistance staff, according to two people familiar with the company’s operations. Those workers intervened to assist the vehicles every two and a half to five miles, the people said.

The expenses associated with remote assistance are one reason robot taxis will struggle to replace traditional ride-hailing fleets operated by Uber and Lyft. Though companies like Zoox are beginning to replace drivers, they still pay people to work behind the scenes.

“It may be cheaper just to pay a driver to sit in the car and drive it,” said Thomas W. Malone, a professor at the Massachusetts Institute of Technology Center for Collective Intelligence.

Waymo and Cruise declined to comment for this story.

While those companies use traditional cars retrofitted for self-driving, Zoox is testing a new kind of vehicle in Foster City, just south of San Francisco, and in Las Vegas, not far from the Strip.

After testing the vehicles with Zoox employees, their family members and friends, the company plans to make the service available to the public this year. But this robot taxi, like all others, will lean on human assistance.

In Foster City, the company operates what it calls a “fusion center,” where employees monitor robot taxis operating both locally and in Las Vegas, several hundred miles away. From their computer screens, these workers can track live feeds of the road from cameras installed on the cars as well as a detailed overhead view of each car and its surroundings, which is stitched together using data streaming from an array of sensors on the vehicle.

The workers can provide verbal assistance to riders via speakers and microphones inside the cars. They can also assist a car if it encounters a scenario it cannot handle on its own.

Self-driving cars can reliably handle familiar situations, like an ordinary right turn or a lane change. They are designed to brake on their own when a pedestrian runs in front of them. But they are less adept in unusual or unexpected situations. That’s why they still need the humans in the fusion center.

But even though self-driving cars have remote assistance, they still make mistakes on the road.

After reviewing the incident, Zoox indicated that its car had struggled to recognize the fire trucks because they were yellow, not red. “We continue to test and refine our driving software,” Whitney Jencks, a company spokeswoman, said.

Zoox will also continue to lean on human assistance.

“We think that computers should be able to replicate humans and replace humans in all ways,” Dr. Malone, the M.I.T. professor, said. “It is possible that might happen. But it hasn’t yet.”

The Polaris Dawn mission that will feature the first civilian space walk is set for Friday after the Federal Aviation Administration cleared SpaceX to use the rocket that will launch the astronauts into the space.

The five-day trip led by billionaire Jared Isaacman, which has been repeatedly delayed, is scheduled to blast off from the Kennedy Space Center on Friday, with backup launch dates on Saturday and Sunday should the weather prove unfavorable or other problems arise.

The latest delay came last week, when the FAA grounded SpaceX’s fleet of Falcon 9 rockets after the first-stage booster of a Falcon 9 fell over and exploded while trying to land on a barge off the Florida coast. The FAA lifted its order on Friday, paving the way for the Polaris Dawn mission, which will use a Falcon 9 rocket.

SpaceX said that the first stage had completed 22 launches and returns before the accident. The mishap also ended a streak of 267 successful returns for the Falcon 9 program, which has sharply lower launch costs due its reusable first stage.

The Polaris Dawn mission had been scheduled to launch early last week but was first delayed due to a helium leak in a launchpad hose that pumps helium into the Falcon 9 engines. Unfavorable conditions forecast off the coast of Florida for the splashdown prompted a second delay.

Isaacman, a fintech billionaire, is funding the space journey aboard a SpaceX Crew Dragon capsule, which typically services the International Space Station.

Accompanying him are three other crew members, including two SpaceX employees. The flight will send them to the highest Earth orbit since the Apollo program, and on the third day Isaacman and a second crew member are set to become the first civilians to walk in space.

They will be testing a new generation of form-fitting space suits that SpaceX says will be necessary to colonize the moon and Mars.

Since the mission is not docking with the space station and has limited supplies, weather conditions need to be good for both the launch and splashdown off the Florida coast.

Alexia Rangel recalled sweating as she rang up customer orders at a Taco Bell in Alhambra during an early August heat wave. The air conditioning wasn’t working, she and fellow workers said, and heat radiated from the grills in the kitchen.

She remembers feeling dizzy a few hours into her shift, then her vision shifting to black and white. The color drained from her face, she said, and her lips turned purple.

“I nearly, almost passed out,” recounted Rangel, 20.

Despite new state regulations requiring workplaces to cool indoor climates when they reach unsafe levels, the temperature in the restaurant’s kitchen that day registered 104 degrees, according to a hand-held thermometer that Rangel said a co-worker showed her. Workers would include a photo of the temperature reading in a complaint filed with state regulators.

After years of delays, California’s new rule regulating heat in indoor workplaces took effect in late July. The rule, adopted by the California Division of Occupational Safety and Health, lays out heat illness prevention measures for indoor workplaces. It requires employers to provide easy access to clean drinking water and cooling areas, and to monitor workers for signs of heat illness whenever work site temperatures reach or exceed 82 degrees.

If temperatures climb to 87 degrees, or employees are required to work near hot equipment, employers must cool the work site or rotate workers out of hot environments. Workers are to be allowed an unlimited number of cool-down breaks to protect themselves from overheating.

But more than four weeks after the regulations took effect, interviews with workers and union leaders indicate compliance varies by industry and workplace. Some workers interviewed by The Times said they continue to swelter. Many weren’t aware of the new rules.

The places where heat safety measures were in effect tended to be union shops where regulations had been written into existing contracts, or in industries such as demolition and hazardous materials removal where such precautions have become ingrained in workplace culture.

While employers have a legal responsibility to implement the new measures, advocates stressed that labor groups and community organizations will need to work with the state to raise awareness of the regulations and ensure employees have the information they need to push for changes. A major challenge will be supporting workers who fear retaliation, labor experts said.

“The timeline should be as soon as possible, because heat was killing workers yesterday,” said Renee Guerrero Deleon, an organizer at the Southern California Coalition for Occupational Safety and Health.

Some occupational health experts worry that Cal/OSHA won’t be up to the task of promoting and enforcing the new standards. The agency is confronting a severe staffing shortage that is hampering its ability to conduct workplace inspections. Cal/OSHA is already under fire for failing to aggressively enforce heat regulations for outdoor laborers, raising questions about its ability to ensure compliance with nearly 200,000 indoor sites.

Cal/OSHA spokesperson Peter Melton said in an emailed statement that the agency has begun “extensive campaigns on social media.” It will continue to ramp up inspections and work to increase hiring, Melton said.

The state estimates the heat standards will apply to about 1.4 million workers. The job sites expected to be most affected include industrial warehouses, commercial laundries, manufacturing facilities and restaurant kitchens.

Employers who fail to comply could face Cal/OSHA inspections and penalties of up to $15,873 per violation; penalties rise for deliberate or repeat violations.

At the Taco Bell in Alhambra where Rangel works, employees initially weren’t aware of the heat standards. Still, they were so concerned about conditions that, days after Rangel nearly fainted, workers held a one-day strike in front of the restaurant. They learned of the new rules while filing a complaint with Cal/OSHA.

Taco Bell Corp. did not respond to specific questions about its compliance with the heat law, but issued a more general statement saying it prioritizes the health and safety of employees. “In this case, the franchise owner and operator of this location took swift action to address the issue,” the company said.

Rangel said the restaurant, indeed, has felt cooler in recent days, adding: “It took for someone to almost pass out for them to do all this stuff, like fix the A/Cs.”

Ana Solis is a dishwasher with Flying Food Group, a catering company that services airlines. She says the heat emanating from dishwashing machines can be suffocating.

(Michael Blackshire / Los Angeles Times)

Ana Solis, 65, is among the workers who said they hadn’t heard about the new regulations until interviewed by The Times.

Solis is a dishwasher with Flying Food Group, a catering company that services airlines. Her work area in Inglewood has air conditioning, but she said that the system isn’t powerful enough to cool a room filled with steamy dishwashing machines.

She said the high heat sometimes leaves her struggling to breathe and with red, irritated skin that she treats at home with creams. Solis said workers at the site are allowed to go to an air-conditioned cafeteria for 10-minute breaks and lunch, but that she sometimes needs additional breaks, escaping to a cool hallway to catch her breath.

“We don’t have the right to a cool-down break,” she said, unaware the new regulations provide that right. “But sometimes I take it, because the heat makes me feel like I’m suffocating.”

Flying Food representatives did not respond to questions from The Times regarding how the company is complying with the heat standards.

Margot Alvarez, an employee with Braun Linen, a commercial laundry company, was among the workers The Times interviewed who said they were unaware of the state’s new indoor heat regulations.

(Genaro Molina / Los Angeles Times)

Margot Alvarez, who sorts soiled bedding and other materials from convalescent homes and medical facilities at Braun Linen, a commercial laundry in Paramount, was also unaware of the regulations.

Hot steam wafts from a large washing machine as she works in a vinyl gown and gloves. She said the heat generated by sanitizing appliances makes the room feel at least 10 degrees hotter than the outdoor temperature.

After Alvarez raised concerns, she said, management installed a fan by her work station. But she said the fan mainly blows hot air in her direction. Twice in recent weeks, Alvarez said, she grew lightheaded and vomited in the restroom.

Scott Cornwell, owner of Braun Linen, declined to comment on specific concerns Alvarez raised. He said his company works closely with the union that represents its workers, and has installed fans and air conditioning. He said workers have access to cooling areas and water.

“We are in compliance,” Cornwell said.

Bertha Servin, 58, works at Mission Linen Supply in Chino, an industrial laundry where workers sanitize and iron linens, uniforms and bedding for nearby hospitals.

“The big industrial machines, the big dryers, the ironers, everything is hot,” Servin said.

But because of long-standing provisions built into their union contract, Servin said, she and her colleagues have access to fans and cooling machines, and workers come together to make requests, such as asking the company to repair a broken ice maker. The contract also requires the company to provide annual training sessions, where workers are told to be attentive to their bodies in the heat and to feel free to go to the lunch room for a cool-down break.

“If you don’t feel good, you have to report immediately to a supervisor,” she said.

For demolition and construction workers laboring on sizzling roofs or handling hazardous materials in humid plastic enclosures, heat has long been a serious threat. Several workers who specialize in asbestos, lead and mold removal said efforts to safeguard against heat illness predate the state standards. Instead, the industry serves as an example of what protocols can look like once they are ingrained in workplace culture.

Often, buildings undergoing construction have the power shut off, which means there is no air conditioning. On some sites, workers wear respirators and protective body suits as they extract hazardous materials. They often are slinging sledgehammers and crowbars “in a sauna-like environment,” said Fabian Plascencia, of the Northern District Council of Laborers Local 67.

Each morning, PARC Environmental, a hazardous services company based in Fresno, convenes a meeting to discuss the dangers presented by that day’s job site, and review a worksheet that outlines safety protocols, including heat illness prevention, said foreman Rodolfo Nunes.

“The company has always been really strict on heat, since we are from the Central Valley. Our guys need to stay hydrated at all times,” said Nunes, 35.

For demolition and construction workers laboring on sizzling roofs or handling hazardous materials in humid plastic enclosures, heat has long been a serious threat.

(Brian van der Brug / Los Angeles Times)

Nunes frequently works in triple-digit conditions. “Oh man, it gets overwhelming,” he said, adding that he’s finally developed a habit of drinking water before he’s thirsty.

“It’s adapting, just getting used to routines,” Nunes said. “When you’re new, you don’t know the first symptoms, like dry mouth. The small things that are going to take you to dehydration.”

Eco Bay, a Bay Area company that does hazardous materials remediation, convened supervisors for a meeting earlier this summer to discuss the new indoor heat rule.

Workers had already been trained to hydrate and take breaks, and to check in with each other for symptoms of heat illness using a buddy system, said Juan Carlos Moreno, 51, a supervisor at Eco Bay. The main changes communicated at the training involved monitoring temperatures throughout the job site and emphasizing to workers that there are no break limits in the heat.

Michelle Moreno, Eco Bay’s safety director, said the company now places thermometers in different areas of the job site and checks them throughout the day to ensure the temperature is under the 82-degree threshold.

During a months-long project inside a poorly ventilated building in the Sacramento area last year, Eco Bay provided workers with respirators that had built-in cooling systems, called a “powered air-purifying respirator.” Moreno said the company’s owner was a laborer himself before he started the company, and so he takes safety seriously and is “more than willing to spend money on it.”

“It comes down to companies having the right culture,” Moreno said, “and making sure people in charge are trained properly to recognize hazards and how to put controls in place, and also training workers so that they know how to recognize warning signs and to speak up if they aren’t feeling well.”

This article is part of The Times’ equity reporting initiative, funded by the James Irvine Foundation, exploring the challenges facing low-income workers and the efforts being made to address California’s economic divide.