Doctor Betti Dr. Betti Hertzberg Ressler is a Board Certified Pediatrician on staff at Miami Children's Hospital. Dr. Hertzberg developed the toilet training video "Let's Go Potty." She is the co-author of "The Doctor's Book of Home Remedies for Children." Croup Question: Croup, which is better, a heat vaporizer or a cool mist one? I am so confused. Renee Answer: Croup is an infection of the upper airway usually caused by a virus. It best responds to humidity. Usually, cool mist seems to help reduce the swelling that is associated with this better than warm mist. There are stories of parents that rush to the emergency room with a croupy child, only to have cured them on the way! The croupy cough, which sometimes gets worse at night, is immediately relieved by driving with the windows open. This in itself works because the "cool" night air is breathed in, in a manner similar to a vaporizer. This in turn reduces the upper airway swelling as well as the cough. Cool mist seems to work best! Dr. Betti Also see: My 10 year old daughter is incredibly prone to insect bites. Even when no one else is getting bitten, they seem to go for her! Any suggestions? My 12 year old daughter experiences difficulty sleeping due to fear of the dark and being alone. Is this normal? Ask Dr. Betti your questions This information is not intended to be a substitute for visiting your pediatrician. If you or your child has specific concerns, you should see your doctor for a diagnosis and treatment.