Carbon monoxide (CO) is a colorless, odorless, and tasteless gas resulting from the incomplete combustion of carbon compounds. CO exposure is highest in enclosed and/or poorly ventilated environments. CO has a high affinity for hemoglobin, forming carboxyhemoglobin (COHb), which impairs oxygen transport and causes tissue anoxia. CO toxicity leads to symptoms ranging from fatigue, headaches, and dizziness to coma and death. On December 13, 2012, an engaged couple disappeared after going shopping at a supermarket in Niterói. Six days later, their bodies were found in a car parked in the garage of the house where they planned to live in São Gonçalo..Forensic examination determined that the garage was completely sealed with inadequate ventilation. The bodies were inside the vehicle, which was turned off but with the key in the ignition and the air conditioning in the on position. Findings indicate that the couple arrived at the location and remained in the car with the engine running, resulting in a lethal accumulation of carbon monoxide. Forensic investigation concluded that the deaths were accidental, caused by carbon monoxide poisoning, although the exact cause of death was listed as undetermined in the toxicological examination. The absence of signs of violence or presence of third parties supported this conclusion. Estimations of carbon monoxide concentration over time indicated that the enclosed environment allowed for the accumulation of lethal levels of the gas, leading to the couple's death.
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