Abstract: At 5:30 p.m. on December 26, 2017, Employee #1 was performing cheese analyses every 45 minutes and creating the associated reports in the In-Process Lab. Unbeknownst to the employee, a boiler combustion chamber weld had cracked, releasing high levels of carbon monoxide into the Boiler Room, and the carbon monoxide gas had also traveled into the In-Process Lab, where the employee was working. The employee was exposed to high levels of carbon monoxide, causing light headiness, nausea, headache, ringing in ears, sweating, confusion and hand-eye coordination issues. Employee #1 was hospitalized with a carboxyhemoglobin level of 27.4%.