I am planning to climb Huangshan on September 10. I want to bring only a small pack for necessities (I am staying overnight at the Beihai Hotel). Do I need to dress warmly at this time of year? Or is a long-sleeve shirt and light pants ok? Less? Also, how much time does it take to walk down from the Beihai Hotel to the White Cloud Stream scenic area? We want to see the 'fairy bridge' and then turn around and go back down to the Yuping cablecar.