Six prisoners in Georgia have had their sentences cut by a quarter as a thanks for coming to the aid of a prison guard who collapsed with a heart attack.

The six men were working outdoors in Polk county, Georgia, when their guard collapsed.

But, instead of grabbing his gun or running off, they helped him.

One inmate used the guard's phone to call 911 while the others removed the guard's bullet proof vest to cool him off, according to a Facebook post from the Polk county sheriff's office.

Greg Williams, one of the prisoners, said that the guard collapsed and initially stopped breathing.

"When he started breathing again, it was just real heavy and real fast," said Williams.

"When that happened, in my opinion, it wasn't about who is in jail and who wasn't.

"It was about a man going down and we had to help him."