Abstract: At 1:40 p.m. on March 2, 2021, Employee #1, a 23-year-old male, was troubleshooting hot spots identified in a thermography report at a worksite. He deenergized the load side and verified zero energy before beginning the task. While checking the tightness of lugs on the load side terminals, Employee #1 determined that the top right terminal was loose. The line side was live, and as soon as he touched the terminal with an Allen wrench, an arc flash occurred. The employee suffered burns to his face, neck, head, hands, and upper body. He was hospitalized for treatment. He was not wearing electrically rated PPE aside from a flame-resistant uniform. This was the first time Employee #1 had attempted this task.