There were a lot of lessons that came out of WWI, including many related to hygiene during armed conflicts. Those who served in WWII benefited from post-WWI research and concern for personal hygiene, sanitation, and overall cleanliness, allowing for a cleaner wartime experience.
WWII hygiene involved a lot of innovation, including everything from chemicals to prevent infestation to footwear designed to keep feet dry and clean. Regulations about water, latrines, and food became far more strict. While some of the efforts to promote hygiene during WWII were more successful than others, troops were given heavy doses of information about how to stay clean and healthy as part of their patriotic duty.
This is not to say that mud, bugs, disease, and filth weren't problematic during WWII. What hygiene was like in WWII came closer to an ideal standard of cleanliness than ever before, but some realities of conflict are unavoidable. This didn't stop the armed forces from trying, however, and unprecedented campaigns to fight afflictions like venereal disease opened up conversations about personal topics for the sheer purpose of keeping servicemen healthy.
To counteract inevitable problems with insects and the diseases they spread, the National Institute of Health in the United States - and its global counterparts - took steps to prevent potential epidemics. In Switzerland, scientists at the Geigy company developed an insecticide called Dichlorodiphenyltrichloroethane, better known was DDT, during the late 1930s. The Swiss chemist who came up with the concoction, Paul Mueller, won a Nobel Prize for medicine and physiology in 1948 for his efforts.
DDT was soon sent to the United States, where scientists experimented with its effectiveness. Dr. Fred Soper, an epidemiologist from the United States, was one of the biggest proponents of DDT, even persuading the Egyptian government to use it to fight a malaria outbreak in 1943 and 1944. With his efforts and the support of the Rockefeller Foundation and other Allied countries, DDT was being dropped directly on millions of civilians and servicemen alike in the Mediterranean and Southeast Asia by 1944.
DDT was easy to manufacture, affordable, and effective. The colorless, nearly odorless chemical wiped out lice, mosquitos, mites, and other bugs, exponentially decreasing the spread of diseases such as malaria and typhus. The immediate success of DDT saved millions of lives and was touted as a solution to typhus, "the dreaded plague that has followed in the wake of every great war in history."
DDT's success on the field resulted in widespread demand for the product, which became available to the public during the late 1940s. Everyone from governments to farmers to backyard gardeners used DDT in abundance, spraying it in the direction of people, plants, and animals. While the public was warned of its potential to "upset the balance of nature," the long-term consequences of DDT remained unknown.
In the years after WWI, the United States government established permanent laundries and dry cleaning facilities at many of its bases around the country. As a cooperative effort among the Quartermaster Corps, the Army Corps of Engineers, and the Laundry Branch of the Salvage Division of the Supply Service, laundry became standardized in terms of process and supplies. Once WWII broke out, the US found itself extending laundry services overseas.
At Camp Lee in Virginia, troops were trained to use mobile laundry machines over 12 weeks. After completing the training, laundry units - made up of three officers and 85 enlisted men - were dispatched. From 1940 forward, mobile laundries resembling semi-trucks contained as many as six units and could wash roughly 125 pounds of clothing each hour.
Officers, enlisted men, and some civilians could pay to have their clothes washed, although the former received preferential treatment. Men paid 50 cents per bundle, as legislation to have laundry service free of charge failed to come to fruition.
Servicemen also had access to public shower facilities. Much like laundries, showers were intended to keep them clean in the interest of combating lice and other infestations while simultaneously boosting morale. Shower facilities could have between eight and 24 shower heads, with additional fumigation areas available.
Venereal disease was rife during WWI, with many veterans bringing syphilis and gonorrhea home with them. As a result, US officials made concerted efforts to help servicemen make better decisions, to conduct medical tests, and to keep detailed records of venereal disease outbreaks. The more active approach, called the Eight-Point Agreement, helped make solicitation in the proximity of bases a federal offense, established "Rapid Treatment Centers" for venereal disease, and fostered strategies for treating disease while allowing men to stay on active duty.
Servicemen had access to penicillin, a relatively new drug purported to have vast success against venereal diseases, alongside standard arsenic and sulfur treatments.
The United States War Department also distributed pamphlets with much more explicit information than had ever been extended to men in service. Men were instructed on how to clean themselves, informed about prophylaxis options, and told to seek treatment immediately should symptoms of a venereal disease arise.
The best way to avoid venereal disease, however, was "to stay away from women," especially a woman who let "you use her, or who 'consents' easily," because she was not "safe."
The US armed forces employed the "Millbank Disinfestor" to rid bedding, clothes, and rugs of lice and lice eggs. Developed in Britain, the Millbank Hot Air Disinfestor and Drying Machine was portable and could rid items of bugs and bug eggs in half an hour. The machine circulated air up to 170°C - roughly 338°F - through a mixing chamber, disinfecting 100 suits at a time. One hundred blankets could be disinfected in a single hour.
The Millbank Disinfestor couldn't keep up with the lice during WWII, however. Reinfestation could happen almost immediately, and the process was relatively slow.