Here in New York we’re currently experiencing the first Seriously Nice Day of the year. And while it’s tempting to fling off winter clothes and embrace sunshine with open arms, we’re exercising a little caution. Our face, arms, and décolletage have all been bathed in a layer of SPF 70, and we’re in a myth-busting mood.

Without further ado, we’re debunking 7 sunscreen untruths. Take notes, and your skin will thank you later.

Makeup’s got you covered – While a foundation or tinted moisturizer with, say, SPF 15 can be great as a little extra insurance, it won’t be enough for any prolonged exposure in the sun. Be sure to use at least SPF 30 as a base, whether it’s an upscale option (Sunday Riley Cashmere SPF 30, as reviewed here), or a drugstore bargain (try Neutrogena Ultra Sheer Dry Touch SPF 55, $9

One application and you’re good to go – Sure, it’s tempting to apply a layer under your makeup in the morning and call it a day (we’re certainly guilty of it from time to time), but medical professional recommend reapplying every two to four hours. A pain in the ass? Sure. Worth it

Cloud cover = a free pass – Were it that that were the case! Sadly, even on cloudy days up to 80% of the sun’s rays can pass through clouds, according to the skincare foundation. Ditto for wintertime; snowfall can reflect UV rays and make you even more vulnerable to harmful exposure.

The myth of the base tan – Contrary to what a perma-bronzed aunt may have told you, getting a ‘base tan’ does not reduce your chances of getting sunburned, and is still harmful to skin.

Free highlights! – In high school we’d often rub lemon juice (or the infamous Sun-In) on our blonde hair and let the sun give us some natural highlights, sun exposure is lousy for locks. It’s damaging, drying, and crispy tresses don’t go with a Topshop sundress.

Vitamin D! – After a (very) limited amount of time, the vitamin D production spurred by sunlight will stop. Any UV exposure after that point breaks down vitamin D to a series of inactive compounds. Your best bet for getting the big D is through a balanced diet and vitamins.

Salons are safer – Tanning under a sunlamp at a tanning salon is every bit as dangerous as tanning outside. A tanner regularly using high pressure sunlamps can be getting up to 12 times the UVA you’d get from sun exposure.