Japanese human experimentation during WW2:

“To determine the treatment of frostbite, prisoners were taken outside in freezing weather and left with exposed arms, periodically drenched with water until frozen solid. The arm was later amputated; the doctor would repeat the process on the victim’s upper arm to the shoulder. After both arms were gone, the doctors moved on to the legs until only a head and torso remained. The victim was then used for plague and pathogens experiments.”