Crew members push Lotus driver Kimi Raikkonen of Finland in his race car to the garage during the first practice session of the Malaysian Grand Prix at Sepang on Friday. The Malaysian Grand Prix will take place on Sunday. [Roslan Rahman / Agence France-Presse]

Tough conditions put extra pressure on men in the hot seats

Nico Hulkenberg keeps cool by freezing his underwear, Valtteri Bottas says the climate is like a sauna, and Giedo van der Garde says the drivers drink so much water they constantly have to pee.

Welcome to life at the Malaysian Grand Prix, where fierce heat and humidity mixed with frequent torrential downpours make for one of the toughest races in Formula One.

As if an abrasive, tire-shredding track and the G-force through a series of hairpin turns is not enough, tropical conditions at the Sepang circuit, built on former jungle just three degrees from the equator, pose a unique challenge.

On Friday, the first day of practice, ambient heat reached 33 C and the track was measured at 41 C, the same temperature as the average bath.

"I don't enjoy the heat and the humidity of the place but the circuit is nice," said Lotus's former world champion Kimi Raikkonen, a winner at Sepang in 2003 and 2008.

Lewis Hamilton put it more directly.

"It's 36 C here and must be about 80 percent humidity, sweating my ass off in this place," he tweeted, before adding: "But it's beautiful here. Tomorrow I get to go to the Petronas Twin Towers, can't wait."

As perspiring fans held iced drinks to their cheeks and sat beneath palm trees for shade, drivers said they eat salty food, drink gallons of water and even train in heat chambers to better cope with the conditions.

"There's not really much training you can do," said Marussia rookie Max Chilton.

"You can do heat-chamber work which will help but the main thing is making sure your body is always hydrated to its absolute maximum."

The only relief comes in the form of rainstorms so heavy that they make driving dangerous or impossible - as seen midway through Friday's second practice session, when a sudden downpour cleared the track.

Hulkenberg acclimatizes by playing tennis in the midday sun, and he also has a special trick - soaking his undergarments in water and putting them in the freezer, giving him a precious few minutes of icy cool.

"You use a different philosophy with food, you use a lot of salt, you drink a lot during the whole day," said Caterham's van der Garde.

"I think we drink up to five or six liters, so you pee quite a lot."

Bottas, in his first season for Williams, comes from the snowy landscape of Finland but he says Malaysia reminds him of one aspect of home - the saunas.

"Of course, we have the saunas in Finland, so maybe that helps with the heat," he said.