David Keeling would take over the workplace-safety agency just as it is considering rules to protect against extreme heat. His former employers, UPS and Amazon, have opposed the rules.

For years, UPS truck drivers asked the delivery giant to install air-conditioning in its ubiquitous brown vans. The company resisted, even as temperatures climbed and drivers suffered from heatstroke.

Now, David Keeling, a former health and safety executive at UPS who some workers blame for the inaction, is President Trump’s pick to lead the Occupational Safety and Health Administration, the federal agency that regulates workplace safety. A Senate committee is scheduled to vote Thursday on his confirmation.

Mr. Keeling, who spent nearly four decades at UPS before moving to Amazon in 2021, would be taking helm at the agency just as it considers the first federal rule designed to protect as many as 36 million workers from extreme heat. Among other things it would