A cold and a cough are usually due to a viral infection, while cetirizine mainly helps with allergic symptoms like sneezing and a runny nose. It may give some relief if your symptoms are allergy-related, but it does not directly treat cough or infection. Simple measures such as warm fluids, rest, and steam inhalation are more helpful for recovery. Avoid cold exposure to prevent worsening. If symptoms do not improve or keep recurring, consult a doctor for proper advice.