Fever, along with a productive cough for the past couple of days, usually points to an acute chest or respiratory infection, most often viral in nature, where the airways become inflamed and start producing extra mucus. When the cough becomes very intense and leads to vomiting, it is usually because thick phlegm and throat irritation trigger repeated coughing spasms, especially when lying down or during the night. Montelukast mainly works for allergic or asthma-related inflammation and does not directly treat infection, while a Levolin inhaler is helpful only if there is wheezing or airway tightening, so these alone may not fully control an infection-related cough. Medicines/treatment should be taken only if advised or prescribed by your doctor. Right now, simple care like warm fluids, steam inhalation, and good hydration can help loosen mucus and ease coughing. Rest, avoiding cold air, smoke, and dust, also helps reduce irritation. If the fever continues beyond a few days, sputum becomes thick or discoloured, breathing feels difficult, or vomiting from coughing keeps happening, a proper medical check is important to rule out a chest infection needing specific treatment.