Dry air can cause your mucus to become thick and hard to break up. Using a humidifier will help moistures your throat and nasal passages to help break it up and relieve your cough. Warm-mist humidifiers tend to be the most soothing for coughs but if you have young children consider the cool-mist humidifiers to prevent burns if they get too close. If you have an asthma related cough, humidifiers are not recommended to help relieve your cough.