When someone's heart stops, most people know every second counts in saving the patient.
What you may not know is that dropping the body temperature just a few degrees can separate life and death.
There's solid science behind a procedure called Cooling Therapy.
Tawana Sample was delivering baby Carl last fall when her heart stopped.
An emergency C-section barely saved the baby.
"When they pulled him out, he was blue," she recalled.
It took 40 minutes and seven electric shocks to bring Tawana back.
"When your heart stops for such a long period of time, you're by definition essentially, you're dead," explained Dr. Omar Lateef.
Tawana was left clinging to life, in a coma.
Her brain cells had begun to die.
That's when doctors Omar Lateef and Richard Temes used this cooling system to drop Tawana's body temperature so much it slowed down her entire system, and that slowed any catastrophic brain damage.
They believe it improves brain recovery by about 20 percent, and saves lives.
"Hypothermia is perhaps the most powerful neuroprotective agent out there," said Dr. Temes.
That's why some major urban areas such as New York, Seattle, Miami, and London now require emergency crews to go to hospitals with cooling therapy in certain situations.
"The nearest hospital is not always the right solution," said Dr. Temes. "You wanna get to the nearest hospital that has the expertise and the facilities to take care of that condition."
Of the thousands of hospitals in the United States, only a small percentage have cooling technology.
In some European countries, it's standard practice for cardiac arrest patients who need it.
Dr. Richard Bernstein heads Northwestern's Therapeutic Cooling Program.
He says there's proof it works, but changing hospital practice is slow.
"80-percent of hospitals that should be doing this are not. It takes a champion and some pressure from patient advocacy groups to make it happen," he said.