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.

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Of all the body functions that humans have to contend with, throwing up has got to be the least favorite.

Unless you’re Matthew Clemmens, the Cherry Hills, N.J., man who pled guilty this week to committing “vomit assault” on police captain Michael Vangelo and the officer's 11-year-old daughter during a recent Phillies game.

Dubbed “Pukemon” by the press, Clemmens stuck his fingers down his throat and purposefully puked on Vangelo, who referred to the experience as the “most disgusting thing” he’d ever seen.

As grotesque as the incident was, things could have been worse. Much like yawning, vomiting can be contagious in humans, triggering a chain reaction like the one depicted in the movie “Stand by Me.”

While some speculate that “viral” vomiting is a survival trait that’s evolved in primates – if an ape eats a poisonous plant and pukes, the other apes eating that plant will do the same and survive – others believe the reaction is more of a toss-up.

“With yawning or vomiting or passing out when you see blood, it’s a variable degree of nature and nurture,” says Dr. Paul Kassab, who practices internal medicine at Seattle’s Virginia Mason Medical Center. “Vomiting is more nurture than nature, I would say, but for those who are sensitive to smell, it’s more nature.”

It mainly depends on the individual.

“If you and I and 10 other people are sitting in a room and one person vomits, I wouldn’t say everybody would automatically vomit,” he says. “One person may turn their head, another may try to help; another may gag or vomit because of the smell. It’s something you can’t predict, although you can predict it for yourself by knowing your own sensitivities.”

Alisha Holdener, 33, of Seattle, says she doesn’t get easily queasy, but her husband is a different story.

“My husband has a really bad gag reflex,” she says. “My daughter puked the other day and he was like, ‘I have to go!’ It just triggers something in him. He can’t smell it or see it, because he’ll throw up, too.”

As for Clemmens -- aka Pukemon -- he won’t be sentenced until July 30, but the consensus seems to be unanimous: he’s a chuck-up.

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