Formula One drivers limber up for 'sauna' heat

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, tyre-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 degrees Celsius (91 Fahrenheit) and the track was measured at 41 degrees Celsius, 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 degrees C here and must be about 80% 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 acclimatises 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 litres, 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.

Any extra preparation will be helpful come Sunday, when drivers may have to grapple with both the heat and the rain during the race.

In 2009, the Malaysian race was called off after a relentless storm, and last year's edition was also interrupted by heavy rain.