Night cough and sneezing. Weight.

My boy seems to perfectly energetic and active all through day,but start coughing and sneezing at middle of night or early morning.he was very allergic in early ages too. Shown some symptoms of wheezing at 3..has been prescribed Montek LC kid for few months one tablet at night. Now he is showing similar condition of high mucus filled feel at night with his breathing rhythm,with cough.Somedays,start sneezing at night,which affect his sleep.the condition started with summer vacation now.what should be the remedy for his condition.what all lifestyle changes he require His weight seems to be above average allowed weight.but he is not bulky or very chubby kind.Non vegetarian but no over eating or much junk foods.He had more wait at all times compared to his age from 10month onwards.His mother is also lean to medium posture but have more body weight than shown in appearance.Both parents have an history of asthmatic allergies. Kindly suggest the precautions ,remedies and life style changes.