Cavendish quits the Vuelta

A relaxed Mark Cavendish (HTC-Highroad) rolls to the start.

A relaxed Mark Cavendish (HTC-Highroad) rolls to the start. (Image credit: Fotoreporter Sirotti)

Mark Cavendish (HTC-Highroad) climbed off during stage 4 of the Vuelta a Espana to Sierra Nevada on Tuesday, apparently suffering from heat and fatigue.