The weather in these cities would be great for vistit. Not too cool nor too hot, you just need jackets and shirts, sweaters would be too warm. For night outing, you may need a sweater. I think the good ones have hair dryer, if don't, you can ask the staff for one. Beijing has many amazing places, you can have a walk in the hutongs, for local food, hutongs is the perfect choice for snacks, but for Peking Roast Duck, you can go to the restaurants. For fresh fruits, you can go to Tao Yuan Xian Gu in Miyun County, there are pears, chestnuts, Chinese dates, Kiwi Fruites, apples there that you can pick. They charge in different ways, some would request entrance fee but the fruites you go would be free, some would not charge entrance fee but the fruites would ne weighted and you need to buy them. About the hot spring, I really don't know whether they are from water heater or natural hot spring, but they are safe.