Since you've clicked on this post, it's safe to say that your face probably feels like it's about to crack off into a million pieces if you, dare, smile too big. So what do you do when the religious application of your most-trusted moisturizer fails you? You become a full-blown adult and invest in a humidifier-or ask your parents for one because it's the HOLIDAYS and they're asking you what you want anyway.

OK, but what actually happens to your skin mid winter?

When ­temperatures dip, so do ­humidity ­levels, causing roughness and ­flaking on your skin's outermost layer: your epidermis. (P.S. Cold wind and indoor heating don’t help, since both deplete the protective ­lipid ­barrier that helps retain moisture.) But dry patches are only one side effect. Dehydration causes your body to overcompensate for lack of moisture by producing more oil, says Dendy Engelman, MD, a dermatologist in NYC, which leaves you with clogged pores and an overly shiny complexion.

How a Humidifier Can Help?

The ideal humidity level is between 40 and 60 percent, says Chad Hyland, an associate merchant at The Home Depot. A humidifier emits moisture (usually via a mist) to get your space to that sweet spot. At home, put it in your bedroom, and apply a ­moisturizer with a humectant, such as glycerin or hyaluronic acid. This acts like a ­magnet to draw H2O from the air into your ­complexion, says Dr. Engelman. Topically, though, try glycerin-rich L’Oréal Paris Age Perfect Hydra-Nutrition All Over Honey Skin Balm, $25.

And how the heck do you maintain a clean machine?

To keep your humidifier running optimally, fill it up with distilled water. If you opt for regular tap, be sure to use white vinegar once a week to ­disinfect and remove mineral buildup (a by-product of tap water). Either way, don’t forget to replace the water daily. Stagnant water can ­eventually become a breeding ground for ­bacteria and mold that can then become airborne. When inhaled, these molecules can cause a respiratory infection or trigger allergies.

4 Humidifiers that won't fail you-or your skin:

If You’re a Germophobe...

It’s important to clean any model regularly, but Dyson’s (Dr. Engelman’s fave) has ultraviolet light technology that helps kill pathogens (AKA bacterium or microorganisms that can cause disease).

If You’re Into Aromatherapy...

The coolest feature on this one: a spot to insert the essential oil of your choice for an extra-sensory experience.

If You’re Tight on Space...

Good things come in small packages-such as this antimicrobial version with a permanent filter.

If You Can't Sleep With Extra Noise...

Not that the other humidifiers are loud, but this one serves up "library-level noise (so it's basically silent), while distributing mist in two directions, making sure the air in your space is fully moisturized.