Norma R. Iacovo still remembers what it was like to be standing on an oil rig off the coast of Texas.

It was the late 1990s, and the rig she visited belonged to Vastar Resources, an independent oil and natural gas exploration and production company where she worked as associate general counsel. Outfitted in jeans, a hard hat and steel-tipped boots, she arrived by helicopter, touching down onto the rig’s massive deck amidst the incessant hum of working people and moving pumps. Industrial equipment provided the only shade.