Polk County Sheriff Johnny Moats said the Georgia prisoners, who all have committed minor crimes, would each have their sentences shortened by 25%.
The work crew had been cutting grass at a public cemetery when the corrections officer who was guarding them collapsed in the heat.
The six men used the guard's phone to call police and began performing CPR.
"When that happened, in my opinion, it wasn't about who is in jail and who wasn't," inmate Greg Williams told 11alive.com.
"It was about a man going down and we had to help him," he continued.
The work crew ran to the lone officer after he fell to the ground and removed his bullet-proof vest to perform CPR.
Rather than take his pistol and run off, they used his mobile phone to call for an ambulance.
"None of my guys ran," the officer told WKYC. "None of them did anything they shouldn't have done."
The family of the officer, who does not wish to be identified, bought a lunch of pizza and cupcakes for his incarcerated rescuers the next day.
Sheriff Moats said that "anytime we have a trustee or inmate crew that goes beyond normal duties, we cut them some extra time off".
The inmates' reaction also "really speaks a lot about my officers too, how they treat these inmates", he added. "They treat them like people. Like family."
Their actions come in stark contrast to two other Georgia convicts who were arraigned on Wednesday on charges of murdering two prison guards while being transported between prisons.
Prosecutors say they intend to seek the death penalty for Donnie Rowe and Ricky Dubose, who were captured in Tennessee after a three-day manhunt.

It says that 750,000 visitors who came to the UK last year experienced a football game, spending Â£595m in total, or the equivalent of Â£776 per fan.
The most popular stadiums for overseas visitors were those of Manchester United, Liverpool, and Manchester City.
The biggest number of football visitors were from Ireland, Norway and the US.
Other countries whose residents showed a passion for English football were Germany, Holland, Japan, China, Australia, and the United Arab Emirates.
Popular clubs for overseas visitors also included Chelsea and Tottenham Hotspur, while many people also made a visit to Wembley Stadium.
The greatest proportion of inbound visitors going to a football match was between January and March.
"Not only do some of the best players in the world want to play in Britain, but their international fans want to follow them here to savour the atmosphere of a match," said Patricia Yates of Visit Britain.
Visit Britain introduced a Premier League section on its website earlier this year.
Its football visitor report was based on a question it sponsored on the 2010 Office for National Statistics International Passenger Survey - a survey of passengers entering and leaving the UK.

The University Hospital of North Staffordshire said the other patients were in a "stable or improving condition".
The Health Protection Agency (HPA) said it was continuing to work with the NHS in Stoke and the city council to identify any sources of the disease.
It said the outbreak was not hospital related and it was safe for patients.
Professor Harsh Duggal, Director of the Health Protection Agency's Health Protection Unit in Stafford, said: "We have been able to obtain detailed information on the movements of those affected.
"We are now working with HPA experts in mapping the outbreak and our partners to pinpoint possible sources, using the information we have gathered."
Professor Duggal said he expected to get more cases "over the next week or so" because of the incubation period of the disease.
Officials have said early signs include flu-like symptoms, with muscle aches, tiredness, headaches, dry cough and fever which can lead to pneumonia.
Diarrhoea and confusion may occur, as well as chest and breathing symptoms. The disease can be effectively treated with antibiotics.
Six US prisoners are being rewarded for saving a prison officer who had suffered a suspected heart attack.
[NEXT_CONCEPT]
The boom in foreign players at Premier League teams is being matched by interest from overseas football fans, says tourist authority Visit Britain.
[NEXT_CONCEPT]
A man is in a critical condition after the number of cases of Legionnaires' disease in Stoke-on-Trent reached 11.