If anyone ever needed a reason to use roll-on deodorant instead of a spray, here’s one: A 14-year-old girl in Switzerland gave herself a case of first-degree frostbite by spritzing spray deodorant way too close her skin. And when a 45-year-old friend tried it because she didn’t believe the teenager, the adult wound up with frostbite, too. The unusual cases of "cold burn" were described this week in the journal Pediatrics, where surprised-sounding scientists verified that, yes, aerosol sprays can cause freezing injuries. It works like this: Pressurized gas in a can cools rapidly when it’s sprayed. At the same time, propellants used to push out the gas have low boiling points. That means the temperature can drop rapidly, from a cozy 69 degrees Fahrenheit to a frigid 5 degrees Fahrenheit within 5 seconds. Frostbite occurs when skin starts to freeze, usually at temperatures between 14 degrees Fahrenheit and 28 degrees Fahrenheit. So when someone like the 14-year-old Swiss girl conducts what she described as a “test of courage,” spraying deodorant within 2 inches of her hand for 15 seconds, the result was a big, red patch of frozen skin. It’s not the first time this has happened. An 8-year-old boy suffered a cold burn after spraying himself with toilet cleaner at close range. Another young boy developed second-degree frostbite on his mouth, including lips and tongue, after inhaling an aerosol propane propellant in an effort to get high. And two teen girls at campout burned their ankles and forearms after spraying deodorant from a distance of less than half an inch. The study authors warn sternly against fooling around with aerosol sprays. But they also conclude that anyone silly enough do it probably won’t listen: “In a majority of cases, the patients were obviously aware that such improper use would cause skin damage.” Have you ever conducted a dumb experiment on your body? Share in the comments section. To read more Body Odd posts, click here. You can also find us on Twitter and on Facebook.