Travelling somewhere humid, or swimming in fresh water? Keeping ear infections at bay can be as easy as taking a few preventive actions.

Well-fitting ear plugs should do the trick, but you can get extra protection by wearing a tight swim cap made of silicone that fits over your ears. Any type of ear plug sold for swimming should work.

“You just need to avoid getting water in your ear, which can be done by plugging them up,” he says. Earplugs designed for swimming are a good option. “Swim plugs are custom-made for each ...