Vicks VapoRub — a topical ointment made of ingredients including camphor, eucalyptus oil and menthol that you rub on your throat and chest — doesn't relieve nasal congestion. But the strong menthol odor of VapoRub may trick your brain, so you feel like you're breathing through an unclogged nose. By contrast, decongestant tablets and nasal sprays sold over-the-counter may narrow blood vessels in your nose's lining, leading to reduced swelling in your nasal passages.

VapoRub has drawbacks in addition to its ineffectiveness as a nasal decongestant. It's unsafe for any use in children under 2 years old. In adults and children age 2 and older, use it only on the neck and chest.

Swallowing a few teaspoons of camphor — one of the main ingredients in VapoRub and other topical medications, such as Campho-Phenique and Bengay — can cause deadly poisoning in toddlers. Topical camphor absorbed through mucous membranes or broken skin also can be toxic. That's why you should never put VapoRub in or around the nostrils — especially a small child's nostrils. And if VapoRub gets in your eye, it can injure your cornea.