SACRAMENTO — América Ramirez Lomeli, named for the Mexican soccer team, did everything right as an immigrant.
Growing up in California’s capital, she excelled in school. She volunteered, racking up more than 2,000 hours of extracurriculars by the time she graduated. She collected toys for the children’s hospital that helped her brother after he fell from a roof, and, at her mother’s command, she stayed calm when police were nearby so they did not attract unwanted attention.

One morning this summer, several days into temperatures above 110 degrees in this farming community, Socorro Galvez, 53, began to feel weak as she picked grapes in the suffocating heat. The green vines suddenly looked yellow, her sweat turned cold and she felt like she was going to faint. It happened again, just before the …