Abstract: At 11:05 p.m. on June 29, 2021, an employee working as a truck driver for a parcel delivery service was feeling ill towards the end of his delivery route at the end of his shift. The illness occurred while the employee was driving the delivery truck. The truck that the employee was driving was the standard truck the employer provides for delivery work. The truck has no air conditioning but the employee had a fan installed to the left of the driver position. The back of the truck is covered with a fiberglass roof. This was the employee's first day back after being out on disability leave for 4 months for an injury unrelated to his work duties. The weather that day was 87 degrees Fahrenheit. The employee started his shift at approximately 9:00 a.m. and was scheduled to make a total of 180 stops. Around 4:30 p.m. with 15 stops left to go the employee began to feel. He tried to lay down in the back of the truck in the package area but it didn't help, so he decided to push through to the end of the shift. When he finished his shift, he contacted a coworker who is also his dad and works as a driver for the employer. He told the coworker he wasn't feeling well and started to head home. On the way home his condition worsened and the coworker took him to the hospital, where he was admitted to treat kidney failure. The employee was diagnosed with cannabis hyperemesis syndrome and mild cannabis use disorder and was determined to be not exasperated by working in the heat.