A transportable hyperbaric chamber called the Gamow bag has been reported as an effective means of treating high-altitude illness. The pressure limit of the original bag is set at 2 psi because of the fragility of the fabric. However, improvement of the hardware to make the bag capable of withstanding higher pressures has made it possible to perform standard hyperbaric oxygen therapy with the newly devised portable chamber, the Chamberlite 15. In this study, the safety of the new bag was examined using healthy human volunteers, and the bag was shown to be usable in clinical emergency cases, such as CO intoxication and decompression sickness. The effectiveness of emergency hyperbaric oxygen therapy was also examined using the CO intoxication model of the rat. It was suggested that hyperbaric therapy was especially beneficial if applied during the first 30 minutes of rescue work. It was concluded that the transportable chamber was a promising emergency tool for CO intoxication.