In fires, carbon monoxide (CO) gas is produced by incomplete combustion. CO strongly binds to hemoglobin in the blood, inhibiting oxygen transport and causing hypoxia. In fact, many cases involve CO/HCN mixed gas poisoning due to the production of hydrogen cyanide (HCN) from the combustion of chemical products [1]. CO is a colorless, odorless gas known as the “silent killer” because it can cause many deaths at once due to diffusion. Currently, the only treatment for CO gas poisoning is oxygen ventilation. Hyperbaric oxygen (HBO) therapy, which involves administering oxygen at 2–3 atmospheres, is considered effective, but it takes time to transport patients to facilities where such treatment can be performed (Fig. 125.1). At present, there are no effective treatments for CO and other fire gas poisonings at the scene, resulting in many casualties. If a treatment that can be administered on-site is implemented, it would be possible to treat gas poisoning before or during transport, allowing doctors to focus on treating burns and other injuries after transport, reducing casualties.