Abstract: At 10:30 a.m. on February 14, 2019, an employee was driving a company pickup truck on a wet two lane road on a run to pick up parts. The employee noticed yellow acrid smoke coming out of the vent and before he could open his window he lost consciousness. The truck ran off the road into a drainage ditch filled with flowing water. A passerby called 911 and the employee was hospitalized with hypothermia, shock, respiratory failure of unclear etiology, hyperglycemic nonketotic state, acute delirium due to toxic encephalopathy and and aortic stenosis. There were no mechanical problems found when the truck when it was inspected following the accident. The symptoms were consistent with an exposure to hydrogen sulfide, but no source had been identified and that could not be confirmed.