Abstract: At 5:02 p.m. on June 18, 2021, an employee was delivering packages from an unairconditioned truck on a clear day with little to no cloud cover and a high temperature of 106 degrees Fahrenheit. According to the employee, the cab of the truck can be up to 10 degrees (cab) to 30 degrees (back of truck) hotter in the truck. CSHO measurements showed that the cab was approximately 2 degrees hotter and the back is 5 degrees hotter than ambient outdoor temperature. He was assigned his own delivery truck equipped with a two-gallon water cooler and other assorted drinks. The employer held a pre-shift meeting discussing heat hazards. During this meeting, he was told that someone would be driving out to meet with him during his delivery that day to check in and provide additional water if required, however this did not occur. The number of packages assigned was not adjusted as a result of the temperature. The employer did not adjust the number of packages assigned to Employee #1 or any other driver to deliver due to the increased temperature. The employee began delivering packages around 9:15 a.m. and took a lunch break at 4:00 p.m. at a restaurant with air conditioning. After approximately half an hour, he began to experience hand cramps and later leg cramps. Attributing this to a temperature shock he then went back outside to his truck and decided to "walk it off" by circling his truck, his off-duty supervisor happened to walk by the restaurant and noticed him acting strangely, recognized the signs of heat illness and called emergency services. The employee experienced tunnel vision and briefly lost consciousness multiple times before being transported to the hospital and being hospitalized.