"The grand prix runs for two hours; it's a long lap on a very demanding course that is pretty repetitive, with lots of 90-degree corners and heavy braking. It's bumpy, which is uncomfortable in the cockpit and makes the demands on concentration very high, and, on top of all that, it is incredibly hot and humid, even though we're driving at night."
Webber highlighted the intense heat as one of the toughest features of the race.
"We are wearing three layers of fireproof clothing. There is no ventilation in the cockpit - even though it is open, the air is directed around the driver as much as possible. With a racing engine behind us, and radiators either side of us, temperatures in there exceed 50C. In a grand prix there is no respite - it's high intensity action for the entire duration of the race, with core body temperatures often higher than 40C and your heart rate above 170 beats a minute. It's a raw environment; there's no comfort, and you just have to get on with it.
"Finally, there's the fact that, by and large, we stay on European time, even though Singapore is six or seven hours ahead of that... It's pretty surreal but it's all worth it - it's a very rewarding grand prix and the tough environment helps makes it that way."

In case, somebody doubts the athleticism of F1, just show them this quote...