In cryonics, cryoprotectant solutions are administered through the circulatory system of the patient so that cryoprotectant enters almost every cell of the body. This process is done near a temperature of O°C (32°F) over several hours, during which the cryoprotectant concentration slowly rises to more than 50%. Isolated organs are subjected to similar protocols in organ banking research. Amazingly, living cells can survive replacement of more than 50% of the water inside them with other molecules — if introduction and removal is done at low temperature.