Nitrous oxide (N2O) is a chemical used as a medical anesthetic supplement, industrial semiconductor cleaning agent, and food additive in the manufacture of whipping cream. Nitrous oxide causes hypoxemia and suffocation during repeated inhalation. In severe cases, it causes coma and death. Some of those who are not aware of the dangers still illegally obtain and abuse nitrous oxide even with the law enforcing its use, and some people seem to have abused nitrous oxide after purchasing large amounts in small containers before the law has taken effect. Deaths from misuse of nitrous oxide are extremely rare in South Korea compared to those from other addictions such as carbon monoxide poisoning. No autopsy or follow-up blood tests were performed in this case.However, this is a unique and rare case in which carbon monoxide inhalation due to the combustion of lightning coal at the last moment overlaps with continuous inhalation of large amounts of nitrous oxide for several days beyond simple hallucination use, and is included in this report with a simple literature review.