Extreme heat - with track temperatures even hotter than those seen in Belgium last weekend - very high speeds, and a relatively small performance gap between the supersoft and soft were the key hallmarks of free practice at Monza today.

Track temperatures peaked at 46 degrees centigrade during the afternoon, with over 30 degrees ambient, and this clearly had an effect on tyre wear and degradation: especially with the supersoft.

The supersoft compound set the fastest time of the day with Mercedes driver Lewis Hamilton, but the performance advantage that it has compared to the soft tyre is reasonably small: about 0.6 seconds so far. There's a clearer gap between the soft and the medium of about 1 second, with all three compounds run today.

This suggests that the soft tyre will be a strong race tyre, although the teams had a good opportunity to assess the supersoft during long runs as well. As usual, the work for teams in FP2 was split between qualifying and race simulations, in order for teams to get an overall picture of wear and degradation with different fuel loads.

Monza contains the highest top speeds of the year, with the drivers coming close to 360kph at the speed trap at the end of the pit straight. With more grip as the weekend evolves, these impressive speeds are likely only to get even higher.

As was the case at the Belgian Grand Prix last weekend, each driver had two sets of prototype soft compound tyres for the Friday free practice sessions only, which did not have any colour markings. A useful amount of data has been collected on these, which will be used to assess whether or not to introduce them as race tyres in future.

Paul Hembery: "We thought that Belgium was hot, but the track temperatures we saw today were even hotter: peaking at 46 degrees centigrade. This will have an effect on tyres, but we have to see what conditions will be like for the remainder of the weekend. Traditionally, a one-stopper has been the winning strategy, but this year we're introducing the supersoft to Monza for the first time. How that tyre - which is about half a second faster than the soft so far - could perform in the race as part of the overall strategy was a big focus of the work in free practice today."

Check out our Friday gallery from Monza, here.