He added that it was important to avoid trauma to the ears - meaning not to pick or prod them, or use ear plugs.

"They can irritate and cause more problems than good," Rosenfeld said.

If a child does get swimmer's ear despite these measures, detect and treat it properly.  If it hurts to tug or pull on the ear, it's likely infected.  In this case, a doctor will prescribe an antibiotic or acid-based drop.