BOSTON -- Only about 5 percent of patients who collapse after a sudden heart attack survive. For those who do make it, brain damage often results.

NewsCenter 5's Liz Brunner reported that a handful of hospitals in the Boston area are using advanced cooling techniques to chill heart attack patients' bodies and protect their brains.

"I speak a little slowly now because of everything," said Ellen Hayes, who had a heart attack.

Hayes' speech is a little slower since her heart attack two years ago, but she's alive and able to speak because doctors put her body on ice.

"I think the cooling certainly played a very major part in getting her back to who she is today," Massachusetts General Hospital Dr. David Greer said.

Doctors have been practicing mild hypothermia on heart attack patients since the 1950s -- cooling patients to between 89 and 93 degrees for 24 hours to protect the brain and buy the body more time to recover.

"You're making the brain be not so needy so it doesn't need so much oxygen. It doesn't need so much glucose in the blood to keep it going," Greer said.

But using ice and cooling blankets made it hard for doctors to regulate the body's temperature, potentially causing more damage. Now, doctors at Massachusetts General Hospital and a few other Boston hospitals are getting better results with a machine called the Arctic Sun.

The device uses foam cooling pads connected to tubes that circulate cold water -- chilling the pads and the patient.

"It helps you to regulate the temperature much more easily. It brings down the temperature much more quickly, and it keeps it right at a level that you need it," Greer said.

Two studies in the New England Journal of Medicine found 55 percent of heart attack patients who underwent mild hypothermia had better neurological outcomes. National guidelines distributed last fall urged hospitals to start cooling heart attack patients for 24 hours to prevent brain damage.

Hayes, who was in a coma for two weeks after her heart attack, is thrilled that being chilled saved her life.

"I'm just utterly amazed, and so gleeful that I can be alive," she said.

Body cooling is also showing promise for traumatic brain injury and stroke patients.