Responding to imagined threats about chemical weapons delivered aerially, the British government intensified its efforts to create gas masks for everyone, testing fit and designs for those who might be unable to wear standard equipment. It did so in an atmosphere where popular culture continued to offer dire imaginings about poison gas’s potential for widespread destruction and where questions about anti-gas protection in the empire continued to emerge. By the start of 1938, the government’s air raid precautions department had developed extensive plans for how to distribute gas masks in case of an emergency across the United Kingdom. However, as it began to unveil such plans further, it encountered resistance from pacifists and antimilitarists as well as some grudging acceptance. The first significant test of these schemes came amid the Czechoslovakian or Munich Crisis in September 1938. On what became known as “Gas Mask Sunday,” the government asked its civilian inhabitants to line up across the nation to be fitted for gas masks. Although the outbreak of war was avoided, the limitations of anti-gas protection and the lack of suitable gas masks for all would propel this aspect of civil defense to the forefront as Britain’s entry into war seemed more likely than ever.