A gamow bag is an inflatable pressure bag that is large enough to fit a person inside. By inflating the bag with a foot pump, the effective altitude can be decreased as much as 1500 meters (5,000 feet). It is primarily used for treating severe cases of altitude sickness.

The gamow bag was named after its inventor, Dr. Igor Gamow, son of George Gamow. Dr. Gamow originally designed a predecessor to the gamow bag called "The Bubble" for high-altitude athletes which would produce more red blood cells to carry more oxygen to the muscles. This in turn would increase the athlete's abilities. However, this invention never really got off the ground despite glowing reviews. The equipment was deemed too bulky and susceptible to overheating.

Dr. Gamow did not give up though and re-designed 'The Bubble' into a bag that could be used by high-altitude climbers.