They will join four other boys who were rescued on Sunday.
"All eight rescued boys today are in good health, none have a fever", Jesada Chokedamrongsuk, permanent secretary of the ministry of public health, told a news conference in Chiang Rai in northern Thailand.
He told reporters the four rescued boys were taken to the hospital in the town of Chiang Rai, the provincial capital, for evaluation.
A total of eight boys have now been brought out of the cave complex. Prime Minister Prayuth Chan-ocha was visiting all eight in the nearby hospital that they were helicoptered to, he said. The 25-year-old football coach may have to wait one more day for rescue.
"So, it's not so much how they'll be feeling in the immediate aftermath - we would expect to see some strong reactions - or not - it depends upon many factors I don't know about".
"We have more expertise than yesterday", he said. "Cave diving requires a lot of training, and it's still risky even for the best cave divers".
In the second day of the long, complicated and high-stakes rescue missions, a second group of four boys emerged on Monday. It ended with their fighting cheer, adopted from the U.S. Navy: "Hooyah!"
He said he sent a small submarine to Thailand; it is expected to arrive Monday night local time.
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Four fellow teammates and their coach, Ekaphol Chantawong, remain inside, with hopes that they will be rescued on Tuesday.
"This morning, they said they were hungry and wanted to eat khao pad grapao", he said, referring to a Thai dish of meat fried with chili and basil, and served over rice.
At the hospital in Chiang Rai, green canvas sheets had been put up to block the entrance from view. A massive worldwide search operation was launched and it took 10 days to locate the boys, who had taken shelter on a dry slope, deep in the complex.
Torrential rain had not affected conditions for the rescue operation.
For the final operation tomorrow, Mr Narongsak said the rescuers would use the same plan with some adjustments because the number of survivors to be extracted would be five instead of four as was the case for the last two days.
The boys have been trapped in the Tham Luang Nang Non cave since June 23 when they and their coach entered and were then cut off by flash flooding.
The safety of the divers, who have meticulously planned the mission, is also paramount. He said it was out of respect for the families whose sons were still trapped in the cave. "We believe that we can do even better and it will be a 100 percent success", he said. They wore full-faced masks "while hanging on to the bodies of rescue divers", Channel News Asia reported.
They were found last Monday by two expert British divers.