If the problem is recurrent,it could be asthma,which you too can make out by placing your ear against his chest or back and if you hear whistling sounds in the breathing,then it IS asthma. Avoid exposure to dust and smoke,and make sure your house is clean and free of fumes. If mild,just give steam inhalations for cold and cough and decongestant nasal drops for nasal block or increased cough on lying down. If you hear whistling sounds in the breathing,you'll have to nebulize him.