EPR involves rapidly cooling a person to around 10 to 15°C by replacing all of their blood with ice-cold saline. The patient’s brain activity almost completely stops. They are then disconnected from the cooling system and their body – which would otherwise be classified as dead – is moved to the operating theatre. A surgical team then has 2 hours to fix the person’s injuries before they are warmed up and their heart restarted.

Source: Exclusive: Humans placed in suspended animation for the first time | New Scientist