Sweat dribbles down the necks of Formula 1’s twenty drivers as they skid across inky asphalt. North of 100 degrees, the track surface temperature is scalding enough to melt thin ribbons loose from the Pirelli tires spinning on track.As far as Central Texas temperatures go, an 80-degree October afternoon at the Circuit of the Americas, the speedway just outside of Austin, is a mild start to the track’s weekend festivities planned around the Formula 1 U.S. Grand Prix. But sitting next to a black tarmac without shade can feel sweltering, and fans are the unfortunate bunch left red-faced.Austin, like most U.S. cities, falls prey to the urban heat island effect. In cities with more pavement and fewer green spaces, sunlight is absorbed rather than deflected,…