Abstract: At 2:00 p.m. on June 20, 2021, Employee #1, a 56-year-old male vineyard worker employed by a winery in Sonoma County, California, completed an eight-hour shift outdoors in direct sunlight. That day, the temperature reached 98 degrees Fahrenheit. After returning home, he experienced nausea, stomach pain, excessive sweating, vomiting, and fainting. He was taken to the hospital and admitted for treatment, including IV fluids and pain management. Although he was later hospitalized again for five days due to a bleeding duodenal ulcer and unrelated surgery, the initial illness after fieldwork prompted a Cal/OSHA inspection, which identified deficiencies in the employer's Heat Illness Prevention Program. The employee was hospitalized for treatment.