What leads to the suddenly increased risk of falling sick in the winter? There could be multiple factors behind it.
During winter, the air is very dry and the moisture present in it evaporates, which means that the virus particles can stay in the air for a long time and are more likely to be inhaled by a passerby.
Cover the mouth while coughing and sneezing, wash your hands or sanitize them from time to time.
Being stressed and not having a peaceful sleep can lead to the weakening of your immune system and you may be at risk of suffering from a common cold.
Being at home for longer durations means that it becomes easier for the viruses to cause common colds, flu and other illnesses to spread from one person to another, simply because you are closer to someone who is contagious.
Rhinoviruses are one of the many viruses that can cause colds during winter. These viruses appear to replicate better at temperatures just below the body temperatures.