Are they coughing the night away? Cough syrup is not always working and it can be frustrating to sit and listen to that constant cough. Try onion! Open up an onion and place it on a plate on the floor in the room where the child that coughs is supposed to be sleeping. You might very well see wonders from this.
Now, if the child is coughing out of allergy or asthma it is important to see a doctor to get proper treatment. The onion is not going to help him breathe properly again but it can also be a help alongside other methods like asthma medications. Try it out!