One of the moments of yesterday’s Hungarian GP, which McLaren’s Jenson Button won ahead of Seb Vettel and Fernando Alonso, was Nick Heidfeld’s explosive incident. The German’s R31 caught fire when exiting the pits for the second time on lap 25, leading to an explosion. He was unharmed.

Apparently, the pitstop took longer than usual due to a wheelnut issue, and Lotus Renault GP believes the R31’s forward facing exhausts overheated while the car was stationary, setting the bodywork on fire. Getting up to racing speed didn’t douse the fire, but made it worse. Heidfeld then parked his car at the side of the pit exit and leapt out. The car’s sidepod then exploded, and other cars had to dodge the debris.

This wasn’t Heidfeld first hot incident this year, as his car also caught fire in free practice at the Spanish GP. “It was a lot more scary. At Barcelona I looked left, saw a small fire and had time to stop. This one, I looked straight, saw the fire and it got hot,” he told Autosport. “I really felt the temperature. It was a bit scary – much more than Barcelona.”

“They are still looking into it. The stop was a bit longer, so that might be one of the reasons, but it is not like the stop was very long – it was not that I was stationary for 20 seconds or something. We are still investigating,” he added.

Their cars may be running hot, but the performance is not. Lotus Renault GP left Hungary without points and have just scored six points in the last four races, in contrast with the 42 points they bagged in the first four races. They are currently fifth in the Constructors’ championship with 66 points, 14 behind Mercedes GP Petronas.