Jeff Olsen: It's easy to find, inexpensive, and effective for treating a lot of winter ailments.

Dawn Davis, M.D.: Petroleum jelly is great, and it's one of a dermatologist's main tips and tricks.

Mr. Olsen: Dermatologist Dr. Dawn Davis says that's because this odorless nearly colorless jelly is so versatile.

Dr. Davis: It sits on top of the skin, like a greenhouse roof, so it's like insulating the skin so that it doesn't lose heat and so it doesn't lose moisture.

Mr. Olsen: One recent study called petroleum jelly the best way to reduce the risk of eczema in newborns. Dr. Davis says because petroleum jelly is chemically similar to proteins in our skin, it's also a good choice for treating everything from chapped lips to dry cuticles, hands and feet.

Dr. Davis: A lot of people also ask about using petroleum jelly in the nares, or in the breathing holes of the nose.

Mr. Olsen: Dr. Davis says you should never use it in the nose of infants and small children. In older kids a thin layer of petroleum jelly can even soothe a tender winter nose. For more information, talk with your doctor or visit MayoClinic.org.