Dante is frightened by Virgil's paleness and worries that their trip is too much for him. Virgil responds to Dante by saying his pallor is a result of the pain and anguish within the pit and not from the stress of their journey.
Those who are in the second circle are convicted for sins of the flesh. Their punishment is to be thrashed about by strong winds without any relief. This is symbolic in that they were swept away by passion. Those sinners must relive their sin repeatedly, without any hope of peace or receiving forgiveness. This is symbolic in their disregard for consequences when they gave in to temptation.