Members of the Unit referred to Yoshimura as a "scientific devil" and a "cold blooded animal" because he would conduct his work with strictness.[58] Naoji Uezono, a member of Unit 731, described in a 1980s interview a grisly scene where Yoshimura had "two naked men put in an area 40-50 degrees below zero and researchers filmed the whole process until [the subjects] died. [The subjects] suffered such agony they were digging their nails into each other's flesh".
In other tests, subjects were deprived of food and water to determine the length of time until death; placed into low-pressure chambers until their eyes popped from the sockets; experimented upon to determine the relationship between temperature, burns, and human survival; pumped full of horse blood; hung upside down until death; crushed with heavy objects; electrocuted; dehydrated with hot fans;[46] placed into centrifuges and spun until death; injected with animal blood; exposed to lethal doses of x-rays; subjected to various chemical weapons inside gas chambers; injected with sea water; and burned or buried alive.
Plague-infected fleas, bred in the laboratories of Unit 731 and Unit 1644, were spread by low-flying airplanes over Chinese cities, including coastal Ningbo and Changde, Hunan Province, in 1940 and 1941.[5] These operations killed tens of thousands with bubonic plague epidemics. An expedition to Nanking involved spreading typhoid and paratyphoid germs into the wells, marshes, and houses of the city, as well as infusing them in snacks distributed to locals. Epidemics broke out shortly after, to the elation of many researchers, who concluded that paratyphoid fever was "the most effective" of the pathogens.
Thousands of men, women, children and infants interned at prisoner of war camps were subjected to vivisection, often performed without anesthesia and usually lethal. Prisoners had limbs amputated in order to study blood loss. Limbs removed were sometimes re-attached to the opposite side of victims' bodies.