Abstract: At 7:00 p.m. on November 25, 2023, Employee #1 began a 12-hour security shift at the YMCA construction site in Andover, KS. The weather forecast for the shift called for 8 inches of snow and below freezing temperatures. The construction site was not completely enclosed and did not have a source of heat to keep employees warm. The employer expected the employee to utilize his personal vehicle to keep warm throughout the cold night shift. Employee #1 called the employer at 9:30 p.m. and informed the deputy chief/supervisor that he had reversed his vehicle inside of the open, covered building in order to avoid snow build-up on his personal vehicle. Employee #1 informed the deputy chief/supervisor that his personal vehicle's interior heater was not working and that he had purchased and brought a portable propane space heater as a substitute. The deputy chief/supervisor instructed Employee #1 to be cautious when utilizing the portable propane heater and to ensure his windows were cracked/not sealed when utilizing the equipment inside of his vehicle. At 6:45 a.m. on November 26, 2023, a coworker arrived at the YMCA in Andover, KS to begin her morning shift. Upon arrival, she found Employee #1 unresponsive in his personal vehicle. Local emergency medical services (EMS) and police arrived to triage the scene. The police report identified a warm portable propane space heater on the floorboard of Employee #1's vehicle. The cause of death was determined to be overexposure to carbon monoxide (CO).