Hong Kong is considered to be quite safe, for both men and women, during the day and at night. Police do patrol frequently, but since foreign visitors are always a target for small crimes be sure to keep valuables in the hotel safe, keep a close eye on belongings, and be wary of people trying to distract you. Be aware that the crime rate increases as you go farther north in Kowloon and into the New Territories. Pickpockets are common, especially in crowded places like the Star Ferry waiting lines or at street markets.
Air pollution is a terrible problem in Hong Kong now. The great industrial transformation of the Mainland is pushing pollution to Hong Kong. Shenzhen which is just across the border, produces vast abouts of air pollution which floats over Hong Kong. It rarely clears up; and is even present several miles out to sea. The dramatic skyline of Hong Kong is fast becoming a distant memory. If you have any sort of respiratory problems, you might want to avoid Hong Kong, as well as most Chinese cities.
In terms of health, vaccination certificates are usually not required, though some immunizations are advisable, such as cholera, diphtheria and tetanus, hepatitis A and B, influenza, polio and typhoid. And be prepared to have your temperature taken as you pass through immigration. For more health information, see the Department of Health website. Although most hotel and restaurant tap water is safe, avoid public drinking fountains. Carry bottled water in hot weather.
