To project, a sleeper is placed into a massive tank called a cradle. The temperature in these tanks are carefully lowered as the sleeper's blood is pumped out of their body and replaced with a special fluid made to keep the organs healthy and the body from decaying. The chemicals, however, interrupt the body's natural activities and cause the projector's heart to stop beating, a process called flatlining. Eventually, the temperature in the tank reaches -80 degrees Fahrenheit, further slowing decay. It takes around five hours for a person to be flatlined, and almost as many to be thawed out and revived.