The human brain uses about 20% of the body’s oxygen supply. Hypoxic brain injuries occur when the brain receives less oxygen than it requires without completely depriving it. This differs from cerebral anoxia, which entails complete oxygen deprivation of the brain. As a general rule of thumb, brain damage that results from loss of oxygen begins at the one-minute mark and can cause immediate or long-term brain damage. Hypoxic brain injury recovery depends on the length of time that the brain goes without oxygen. Brain cells begin dying after the first minute of oxygen loss. Neuron sustain extensive damage after three minutes of oxygen deprivation, increasing the chances of lasting brain damage. Death becomes imminent at the five minute mark after oxygen deprivation — even when an oxygen supply is restored. An unusual but effective preventative treatment for brain damage includes therapeutic hypothermia, or what is referred to as “brain cooling.” This process involves reducing the patient’s body temperature to a subnormal level to chill the brain and slow metabolic processes. This reduces the amount of oxygen needed by the brain and aids in slowing the processes that result in brain damage.