A British baby boy was chilled for four days to save his life after he suffered heart surgery complications, Sky News reported.

Finley Burton, from County Durham, northern England, was 16 weeks old when a hole in his heart and a narrowed aorta were repaired by cardiac surgeons.

But the baby developed a rapid heart rhythm of around 200 beats per minute, which could have killed him.

Doctors at Freeman Hospital, Newcastle, decided to cool the sedated child in a special blanket filled with chilled air to allow his heart rate to slow down. His temperature was lowered from about 97 degrees to 92.1 degrees.

"Obviously, if babies were awake and conscious throughout, they would be very uncomfortable," Paddy Walsh, a children's cardiac nurse said. "But they are kept very sedated, so they are not fighting it and are asleep."

Finley was treated a month ago and has since made a "super" recovery, Walsh added.

The hole in Finley's heart was causing his lungs to work too hard, making him breathless and too tired to eat properly.

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