LAS VEGAS — The temperature outside at around 4 p.m. Tuesday was a scorching 113 degrees Fahrenheit (45 degrees Celsius).

The air-conditioning system inside the Knuckleheads Boxing Gym on Bermuda Lane, a few miles from the Strip, simply couldn’t fight off the heat and the constant blowing of hot and oftentimes suffocating air.

But the searing conditions got worse when Manny Pacquiao started working out with just four days remaining before attempting to knock the World Boxing Council (WBC) welterweight crown off Mario Barrios’ head this Saturday at the MGM Grand.

Before a big crowd at the gym, Pacquiao took the opportunity to show off by firing fiery combinations aimed at chief trainer Buboy Fernandez’s banged up pads.

In one instance, Pacquiao even conducted an impromptu clinic with Tokyo Olympics bronze medalist Eumir Marcial and a few other MP Promotions talents in the house hearing his teachings.

At this stage of the buildup, Pacquiao is just trying to maintain his condition.

All the hard work had taken place in Los Angeles where he set up camp starting the third week of May and the remaining days — Wednesday and Thursday — would all be devoted solely to ensuring that he doesn’t suddenly go off.

“We just have to pull him back because great fighters like him tend to over-train. We’ll just make sure he remains in shape and keep him right there and ready to go,” Pacquiao’s Australian strength and conditioning coach Justin Fortune said.

It seems that Pacquiao, who at 46 will be bidding to become the second oldest world champion in history, knows what to do that he didn’t even attempt to extend his training session.

Unlike at the Wild Card Boxing Club in Hollywood where he kept on overextending his workouts, it wasn’t the case during his first training session in Sin City.

And it would likely be the same thing when he does his last two workouts before the official weigh-in this Friday at the Grand Garden Arena.

“I know I am no longer as young as before and the body needs recovery so that’s what I have been doing in this training camp,” Pacquiao said, “and I feel very, very good.”

“I feel great.”

On Wednesday, Pacquiao and Barrios will face off in a press conference at the Studio A and B of the MGM Grand with the big disparity in size and youth on full display.