Cyronic freezing has long been scoffed at by the science community.
But despite that, some people remain convinced that if they can preserve their bodies immediately after death, one day in the future the technology will exist to bring them back to life.
The first person to cryopreserved was Dr. James Bedford in 1967. Around 250 people have been preserved in the US, and another 1500 have made arrangements for this to happen when they die.
Science journalist and author, Helen Thomson has been investigating cryogenics, the latest developments and the complex laws around it.. including talking to those who freeze the dead for a living, and getting a tour of a planned state of the art cryopreservation centre in Texas, called Timeship.
Helen Thomson talks to Jesse Mulligan.