Teams are bracing for a “very demanding” race in tomorrow’s Suzuka 10 Hours amid near record temperatures and humid conditions on the physically demanding Japanese circuit.

Sunday’s penultimate round of the Intercontinental GT Challenge season is set to be one of the hottest races of the year, with a high of 95 degrees Fahrenheit forecasted and heat index in excess of 105 degrees.

It’s likely to not only result in single-stinting tires but single-stints from the drivers as well, who have described the scorching conditions from “tough” to “concerning” and “bloody hot” throughout the weekend so far.

“The ten-hour will be equal to 24 hours, in terms of what it will request for the team and drivers in terms of heat,” Porsche’s Fred Makowiecki told Sportscar365.

“For sure it’s really hard. Some cars with A/C will get an advantage.

“Driver-wise, we will need to take care of ourselves in the car because it will be tough to do 30 laps in good shape.”

Makowiecki, who put his No. 911 Manthey Racing Porsche 911 GT3 R sixth on the grid, said it will “for sure” be the toughest race of the year for drivers.

“It’s reminded me of the beginning of my career when I got my shoe melted on the pillar box on the Viper,” he said. “Everything was melted.

“What’s really hard is to stop [in the pits]. Even if refueling is only 35 or 40 seconds, to stay 40 seconds in the car when it’s bloody hot, you can burn yourself. And if you want to restart, you are very cooked.

“That’s why it’s better to jump out, refresh and come back in.”

The Frenchman’s co-driver, Dirk Werner, agrees that single-stinting will be the norm on Sunday.

Werner said modifications have been made inside the cockpit of their Porsche in order to improve ventilation, with the team utilizing cool-suits instead of an A/C system this weekend.

“In every aspect for the driver it will be really tough,” Werner said. “Yesterday we did a long run in the practice and after 15 laps it was so hot I thought asking if I could stop the long run.”

Chris Reinke, Head of Audi Sport customer racing, believes drivers will be “at the limit” tomorrow due to the extreme temperatures and fatigue related with the 3.6-mile 18-turn circuit.

“I think it’s very demanding to the drivers,” Reinke said. “My biggest worry at the moment is the operator and not the machinery.

“The finish of the race should be in cooler temperatures back again, so I think that’s the most important bit. You’ll be on full power for the end of the race.”

IGTC title contender Tristan Vautier believes the team and manufacturer that best manages their tires will come out as the big winners.

Each car is permitted up to 15 sets of Pirelli P Zero DHD2 tires for the entire weekend, with most teams having conserved their allocations for the race.

“Everyone is concerned about how bad the cars are going to get after half-an-hour or 35 minutes on the tires,” Vautier told Sportscar365. “We’ve focused on that in practice.

“We think our car is relatively strong but it’s hard to know.

“Some cars seem to stand out more in the heat, some more in the cold. The Ferraris have been very strong all around. The Nissan has been stronger than what we can see.

“I think nobody knows what to expect.”