Watching today's practices in an air-conditioned office wearing cotton shirts while many complained about the heat, there was full respect for our drivers out on track who, wearing the regulation four layers, faced huge physical exertion and constant high level g-forces. In air temperatures of around 35°C, David, Christian and Robert each wore a layer of Nomex fireproof underwear (with mandatory long trousers, sleeves and collar), a Nomex balaclava, a lined racing helmet, gloves, socks, boots and a three-layer Alpinestars racing suit (one layer of ventilated felt between two layers of ventilated Nomex).

Try walking the length of the paddock in all that kit, let alone driving an F1 car round a circuit! On track, the extreme heat can cause the car's cockpit temperature to rise to 55°C and, as the heat gets trapped there, for the drivers it's a bit like sitting in an oven.

David Coulthard: "A normal Friday really. Restrictions apply to the overall mileage, even though it's a fresh engine so we didn't do so many laps today. It's much harder on tyres here than in Bahrain and, as we were trying to save tyres for tomorrow's qualifying and the race, we only used one set today. Therefore it was really just a balance evaluation day. The balance seems a little bit better than it was at the last race, so I'm optimistic as to what tomorrow can bring."

Christian Klien: "I only used one set of tyres today. They were graining a lot which caused a lot of understeer. It wasn't really such a good day for me. We have to look at the data tonight and see what we can improve for tomorrow. One thing I can say - it's bloody hot in the car! We only did a few laps today and then the heat's not so bad. It's during the race that you start to get really hot, it begins in your body and then moves up to your head. Last year during the race, I had to open the visor of my racing helmet a little to try and get some air in!"

Robert Doornbos: "We had a busy programme this morning, which was when we did all our tyre testing. It's really important here to chose the right ones. This morning we were gathering data and doing long runs, which was different to the programme I followed in Bahrain last week. It's all good experience and I'm loving it."