Abstract: At 6:00 p.m. on September 7, 2023, an employee was delivering packages. The employee was exposed to the hazard of high heat from direct sun and radiant heat during the performance of his job duties, including loading his vehicle with packages, sorting packages, retrieving items, lifting packages up to 50 pounds or more, collecting signatures if needed, upkeeping of the vehicle, and driving to multiple locations. The packages were varied in size, weight, and quantity, which contributed to the physical demand put on the driver to lift and deliver packages in a productive manner. The National Weather Service issued a heat advisory that included the worksite in Austin, TX, on the day of the incident. 9 Line Transport Inc. is a third party contractor that assists in conducting deliveries for Amazon's distribution warehouse. Employees routinely work outdoors in excessive heat conditions. The hazard associated is working in excessive heat conditions when performing multiple deliveries, while not having access to a cool down area. The employees deliver packages varying in size, weight, and quantity to various locations, while being exposed to the heat inside the vehicle and heat produced when stuck in traffic. The employees do not have air conditioning in all the vehicles, and while making deliveries spend several minutes looking through their cargo to find the packages that need to be delivered. Working in a metal shell truck increases the outside temperature about 10 degrees per every 5 minutes sitting in the sun. Employees have limited means to regulate their body's temperature due to the physical demand of delivering multiple packages at a rapid pace; then, getting into a hot vehicle, it is difficult to dissipate their own metabolic heat. The detective reported that the temperature inside of the truck was 105 degrees and it did not have A/C. The employee died of cardiac arrest with heat-related illness playing a factor.