Downtown Shenzhen. Reminds you of which city? I found the cool weather in January just right. It drizzled on certain days with the skies grey most of the time.
Public buses are air-conditioned and cheap. One yuan can take you on a half hour's trip. But you have to fight with the huge crowd. Taxis are cheap and plentiful. I took taxis in Shenzhen but buses (less crowded) in Hainan Island.
Fortunately, the sidewalks in China are very wide, some as wide as a four-lane road.