How to prevent Common Cold: the disease is usually caused by viruses. Frequent hand washing, covering of nose while sneezing/coughing, plenty fruits and vegetable in diet are helpful in preventing the spread of this condition. Garlic (either raw, cooked or pharmaceutically processed type which has minimal odour) is effective in both treatment and prevention of Common Cold. Maintaining optimal body temperature and avoiding damp housing are beneficial. Stress and lack of exercise are known to generally reduce immunity, so tackling these can be helpful. Air conditioners can harbour organisms that can cause common cold like symptoms, and a such they need to be properly and regularly maintained.