Walt Disney, center, shows off his studio’s proposed design of the Mickey Mouse gas mask in January 1942 to Col. George Fisher, left, chief of the Civil Defense Division,Walt Disney, center ...

M50 Gas Mask demonstration at Eastern Washington Regional Science and Engineering Fair at the Spokane Washington State University campus, Washington, March 15, 2018.U.S. Air Force photo/Senior ...

As explained in a passage from A History of the World War, here's how the gas masks worked: The perfected gas masks used by both sides contained a chamber filled with a specially prepared charcoal.