Ahead of today's opening session, the air temperature is 36 degrees C, whilst the track temperature is 52 degrees.

Tyre options this weekend are medium and soft. There are two DRS zones, the first on the back straight, between Turns 10 and 11, and the second on the pit straight.

There are a couple of reserve drivers on duty today, Jolyon Palmer is back in the Lotus, taking over from Romain Grosjean for the second successive weekend.

All eyes on Mercedes this weekend following last week's spat which, if nothing else, might see Nico Rosberg raise his game a little. Let's not forget that it was here twelve months ago that the gloves on the Mercedes pair finally came off... and didn't we, the fans, enjoy it.

Ferrari should benefit from the warmer temperatures this weekend, with Sebastian Vettel and Kimi Raikkonen both keen to take on the Silver Arrows.

As the lights turn green there is a queue at the end of the pitlane, Hulkenberg leading the way. In moments, all but Ricciardo, Sainz and the Mercedes duo are on track.

With the European season getting underway in there weeks, that's when the real updates will come, however, most of the teams are running new stuff here today.

An early problem for Button who has spun coming out of T1 and is left stranded in the middle of the track facing the wrong way. Even a number of replays don't reveal what went wrong, meanwhile, as the Briton walks back towards the pits the marshals push his car to safety.

Rosberg posts the first time of the day, the German crossing the line at 1:40.077. Shortly after, teammate Hamilton posts 41.147 to go second.

Bottas's Williams is sporting impressive sensors as the Grove outfit seeks to find where it is missing out on downforce.

Fifteen minutes in and Ericsson and Stevens are the only drivers on track, surprising really when you consider that the teams only have another fifteen minutes with the 'free' tyres. Then again, the new limit on power units is causing teams to strictly limit their running.

A 39.676 sees Ericsson go quickest with Stevens only managing 45.727. Massa goes fifth with a 48.431.

Bottas goes top with a 39.206 as more drivers head down the pitlane, amongst them the Ferrari duo.

Massa, a two time winner here, improves to third (39.731) as teammate Bottas locks-up after passing one of the Manors.

Vettel eclipses Bottas by 0.004s as Verstappen makes a mistake and locks up in T1.

As Raikkonen posts 38.975, Vettel reports a loss of power and is immediately told to slow down and return to the pits. He obliges. Elsewhere, Maldonado goes cross-country at T10.

Raikkonen improves with a 38.917 as Kvyat goes quickest in S2, finally crossing the line at 39.399 to take fourth.

Perez goes sixth (39.730), ahead of Massa and Rosberg, as Button remains the only driver yet to post a time.

In the Ferrari garage Vettel is out of his car and his mechanics are working at the back of the car, the engine cover removed.

The opening half hour comes to a close with Raikkonen quickest, ahead of Vettel, Bottas, Kvyat, Ericsson, Perez, Massa, Maldonado, Rosberg and Sainz.

"Unsurprisingly the drivers are reporting tricky and low grip conditions out there in the very high temperatures," says Mercedes.

After a brief lull, Hamilton fires up his engine and heads down the pitlane, shortly after he is followed by his teammate.

This being the only session to take place at this time of day, the remainder happening much later when grip will be significantly higher, it is pretty insignificant, further reason to limit running.

Vettel chats with Marc Gene in the Ferrari garage as work continues on his car.

Rosberg improves to fourth (39.293) and Hamilton sixth (39.532) as they are eventually joined by Perez, Palmer and Hulkenberg.

A big lock-up for Hamilton in T8 flat-spots his tyres as Rosberg is told to think about his "right hand magic". The mind boggles.

Perez goes quickest in S1 and again in S2, as Palmer goes fifth overall (39.283). The Mexican subsequently posts 38.793 to take the top spot.

Hamilton radios his team to advise that his 'hot seat' problem has returned.