Bad circulation causes health problems. Follow this advice to keep your blood moving The feeling is all too familiar: your nose is cold, your legs heavy and your fingers and toes stiff as icicles. For many, central air-conditioning in offices has become an occupational hazard. Wrapped in pashminas, which have gone from fashionable accessory to daily necessity, we sit at our desks shivering, barely able to type. While air-conditioning may be good for circulating the air, it is the main cause of poor blood circulation. With winter around the corner, the cold will get to us in our homes as well, particularly in Hong Kong's poorly insulated apartment buildings. 'Cold air temperature causes blood vessels near the skin to shut down, keeping the blood deeper in the body and the core of the body warm,' says Dr Jonathan Ng, a medical practitioner in Causeway Bay. Our body's natural defence against the cold redistributes the blood to areas that need it most. Therefore, less blood is distributed to extremities including our hands, feet, nose and ears, leaving them cold and pale. Poor circulation can trigger a number of health problems, so it is worth familiarising ourselves with the remedies available.