Prandelli said there was no point in being negative after the loss which left his side needing at least a draw against Uruguay in their final game to qualify from Group D.
"Right now I don't think we need to be negative, we need to think about recovering our energies because we have another game in a few days' time, we play against Uruguay and whether we qualify depends on that," Prandelli told reporters.
"It's useless to blame the heat," he added. "We have to regain not just the physical energy but the mental energy as well."
Italy's first match was in Manaus, in the heart of the Amazon rain forest, and they will face Uruguay in a 1300 (1600 GMT) kickoff on Tuesday in Natal, another tropical venue.
"We know about the calendar, we've known it for some time," said Prandelli. "It's useless to try and find excuses, we're not looking for excuses, we have to be ready at the kickoff."
Prandelli refused to blame Italy's tactics for the defeat.
"We didn't get our tactics wrong," he said. "They were very, very aggressive and we were trying to find different ways into the game but we didn't manage it.
"Mario (Balotelli) had two opportunities and if we had scored the game would have been different.
"All we needed was an opportunity, maybe we should have believed in it more.
"We conceded the goal and that was the end of it. We were unable to come back, congratulations to Costa Rica."
Italy's defeat almost meant that England were eliminated.
"I'm terribly sorry, not just for the English, but also for us," said Prandelli. "We also wanted to win. I have no message for the English."