Abstract: At approximately 4:00 p.m. on July 9, 2008, Employee #1 was working in a field, identified as TD Donahue 35-1. It was located near the intersection of I-5 and County Road Number 7, in Orland, California. Employee #1 was setting a concrete plug after the crew moved Rig Number 307. On July 7, 2008, Employee #1 experienced first symptoms of heat illness. While putting clamps on the tongue line of Rig 307 and reaching the landing, approximately 10 ft above ground level, he began to feel disoriented. He sat down and did not respond to calls from personnel below, for approximately 5 minutes. Employee #1 regained himself; however, he sustained severe cramps and another employee took him home. On July 8, 2008, Employee #1 managed to work the entire day without any incident. At the end of the shift on July 9, 2008, Employee #1 began to vomit. He ended his shift and returned home, where he fell in his restroom. Employee #1's spouse and father-in-law took him to Oroville Hospital in Oroville, California. Employee #1 sustained heat illness and was hospitalized.