Ahead of today's second practice session the air temperature is 27 degrees C, while the track temperature is 55 degrees. It remains hot.
Lewis Hamilton and his Mercedes teammate set the pace this morning, the Briton 0.607s clear of the third placed driver, Kimi Raikkonen. If we were expecting the absence of FRIC to make itself felt this weekend the silver cars aren't showing any sign of it.
Both Ferraris were on the pace earlier, as were Red Bull, McLaren and Toro Rosso, whilst Williams, which is expected to suffer from a lack of downforce, hasn't really played its hand yet.
As ever, the green track has caught a number of driver out but nobody coming to grief.
Tyre choices this weekend are medium (prime) and soft (option), while the two DRS zones, which share a detection point 5m before Turn 14, are 130m after the apex of Turn 14 and 6m after the apex of Turn 1.
As in Germany the high temperatures were leading to tyre degradation this morning, and will be interesting to see how the options stand up this afternoon.
The lights go green and Chilton, who missed almost all of this morning's running due to an oil lead, is first out of the box. Ericsson, Kobayashi and Hulkenberg follow.
Chilton posts a 34.426, but this is soon beaten by Ericsson (34.239), both Caterhams out-pacing the Marussias in FP1.
Next time around Chilton has a moment in T2 as Ericsson and Kobayashi are clearly struggling for grip. Magnussen also, the Dane running across the gravel at the T6/7 chicane.
"Something has changed," says Chilton, "the car is now horrible to drive.". Elsewhere a spin for Maldonado in T9.
As Alonso goes quickest (27.199), teammate Raikkonen is told that the team are aware of an issue with his rear wing.
Just twelve minutes into the session there are 15 times on the board, Alonso ahead of Button, Hulkenberg, Kvyat, Maldonado and Vergne.
On his first flying lap Vettel goes second (27.740), the German appearing to have rediscovered his mojo in the last fortnight.
Having gone quickest in S1, Rosberg loses time behind Vettel but still manages to post a 27.112 to go quickest. The Red Bull driver subsequently posts a 26.949 only to be pipped by Hamilton moments later (26.225).
Twenty minutes into the session everyone bar Grosjean has posted a time, the Frenchman's car being worked on in the Lotus garage.
Both Red Bulls are smothered in flo-vis, Vettel having as nightmare as he gets out of shape in T5 and then out-brakes himself at the chicane.
As Raikkonen locks-up in T2, Hamilton runs wide in T7 as drivers continue to be caught out.
A nice slide for Alonso coming out of the final corner as the F14T appears to switch from oversteer to understeer and back again in the same corner.
Vergne continues to struggle to remain on the black stuff, the Frenchman really battling the Toro Rosso.
With 59:00 on the clock, Hulkenberg is the first driver to make the switch to the option rubber. He improves from 28.338 to 26.870 on his first lap.
As Ricciardo makes the switch to options, Hulkenberg, after a cool down lap, improves to 26.789.
Kobayashi has a big spin in T8, the Japanese lucky not to clout the barriers as he struggles.
On the softer rubber, the Red Bull duo go quickest, Vettel posting (25.111) and Ricciardo (25.983).
As Hamilton fits the options, Bottas goes third with a 26.053.