Some people associate exposure to the cool air from air conditioners as a cause of colds. Again, it is not the temperature that is the culprit. Air conditioners remove moisture from the air which, in turn, can dry the mucous on the nasal membrane. Without a sufficient mucous layer covering these membranes, the nose becomes more susceptible to viruses that cause the common cold. People are most infective or more likely to be able to pass on a cold around two days after they were infected.
People can cough or sneeze out in droplets of mucus containing the cold virus.
Flu symptoms usually occur very quickly after one is infected but the onset of cold symptoms can be up to a couple of days or so. Symptoms like headaches, fever and muscle aches and pains are usually associated with influenza but someone with a severe common cold can also have these symptoms. You cannot cure a cold but you can help protect yourself from getting a cold by following good personal hygiene practices. A healthy diet and getting sufficient sleep are also important in helping to prevent colds. Our immune system is also affected by stress.