The highest temperature seen on track last year was 57 degrees centigrade during the Brazilian Grand Prix weekend – and that record came close to being beaten today, with track temperatures in Sepang that peaked at 56 degrees in FP2.

In these tough conditions, with high-energy corners and significant downforce loads, wear and degradation is inevitably high, with low grip due to surface overheating. So far, there is a performance gap of 0.9 to 1.0 seconds between the P Zero Orange hard and P Zero White medium compounds that have been nominated for this weekend.

Ambient temperatures were just as debilitating as the track conditions, peaking at 36 degrees centigrade, with high humidity. Consequently rain is a constant risk, with some wet weather a possibility for tomorrow. This year's race also has an earlier start time compared to last year, which could increase the likelihood of a wet race. Track temperatures during the race are also expected to be higher than last year.

Mercedes was quickest in both free practice sessions today, with Nico Rosberg in FP1 and Lewis Hamilton in FP2. Both fastest times were quicker than the equivalent times last year.

Paul Hembery: "If these conditions persist until Sunday, we'll be racing in what will almost certainly be the hottest conditions that we experience all year, which obviously provide a proper work-out for the tyres. The medium compound is suffering a bit more than the hard tyre here, which is what we expected, with the front-left being the most critical tyre for drivers to watch. Despite that, we've got no blistering so far and a gap of 0.9 to 1.0 seconds between the two compounds so far, which should open up a few strategy options. However, the unique weather means that Malaysia is one of the hardest races to predict all year, so there's plenty more action to come."

Check out our Friday gallery, here.