T-shirts were required on the verge of the Valencia urban circuit on Thursday as the Spanish port city turned on a warm day.

Ambient temperatures should remain around 30C throughout the weekend, with the only (remote) possibility of a shower scheduled for Saturday.

Most drivers spent Thursday walking the new layout, which winds past the headquarters of some America's Cup teams on the city's port.

At one point, unique on the F1 calendar, the cars will cross a swing bridge, which at other times can rotate to allow boats into the harbour.

Many drivers spent time bending down to evaluate the 3cm gaps between the bridge's connecting pieces.

"It seems it has caused a few issues in F3, so we will monitor the situation very closely," Toyota chassis boss Pascal Vasselon said.

Source: GMM