MILWAUKEE -- Froedtert Hospital in Milwaukee is freezing patients to fight the effects of cardiac arrest.

Video: Hospital Chills Patients

Doctors drop patients' body temperature to save their lives, WISN-TV reported.

Six months ago, Ken Alvord suffered a heart attack and woke up three days later in Froedtert Hospital.

He said he was under a pile of blankets and shivering.

"It was the coldest I've ever been," Alvord said.

Doctors said that's exactly what they wanted. They cooled down his body temperature to 91 degrees to combat the damaging effects of cardiac arrest.

"They lose blood flow to the brain, and the brain can tolerate that for only about two to four minutes. After that, the brain cells begin to die and they release toxins which then can cause further brain damage," Dr. James Kleszka said.

To create the saving effect, the emergency room packs the patient in ice, then he is hooked up to a thermo-cool machine.

"[The] machine then pumps ice-cold saline through balloons and through the catheter. The saline doesn't enter the bloodstream, it just enters the catheter. When the blood passes the catheter, it cools," Kleszka said.

Kleszka said that 75 percent of cardiac arrest patients die, and the rest never fully recover.

However, he said 50 percent of patients treated with the new procedure have walked out of the hospital and returned to their normal lives.

Froedtert was one of the first hospitals to perform the procedure.