Rosa Villegas woke up at two in the morning on a late August Monday to make her way to the lettuce fields in California’s south Salinas Valley, where she was scheduled to start bagging heads of romaine at 4 a.m. The sky overhead wasn’t its usual dark, star-dotted self as she walked to her car. Instead, it glowed a sickly red, colored by the fires burning on the flanks of the Santa Lucia mountains, just a few miles west.