It can be, yes - in the summer months between June and September, the heat and humidity can make city living somewhat uncomfortable, and a lot of people spend as much time as possible indoors. Air pollution is considered bad around 30% of the year and arises from heavy traffic, power plants and air pollution from industrial production in nearby China. Most properties and offices will have high-quality air conditioning, and it is advisable to wear a facemask, particularly when commuting.