Good advice along with a humidifier as someonelse mentioned. Make sure he has plenty of fluids. Someone else mentioned honey which works well with older kids. It's questionable to give honey to a 9 month old. Check with doc on that one. Wow, already 9 months old, time flies. I hope he feels better soon! Make sure his room doesn't get overheated on the cold nights too, that dry heat worsens the cough. Good luck!