And once you hit a certain threshold? “Your DNA is damaged and you’re more prone to skin cancer,” Dr. Rokhsar says.

So get your facts straight: Tanning beds are no safer than straight-up sun exposure. “Ultraviolet rays are ultraviolet rays, it doesn’t matter what the source is,” Dr. Rokhsar says. And if intention counts for anything, then the strong rays you soak up from sun lamps are surely worse than sunshine because you subject yourself to them for the express purpose of tanning your skin.

That could explain why indoor tanning is directly linked to an increased risk of cancer — regardless of whether your skin burns when you hit the beach after. “Tanning beds are just as bad as smoking because melanoma just is as deadly as lung cancer,” Dr. Rokhsar adds, just to drive the point home.

Really, there’s no such thing as a healthy tan. A tan is just a sign that your skin is damaged — no matter where or when you got your glow (and whether you were wearing sunscreen).

So what can you do before takeoff to protect your skin, besides packing copious amounts of sunscreen and a cover-up? Talk to your doctor about tapering off antibiotics and any other remedies that make your skin more sensitive to the sun (just check the labels).

You’ll also want to lay off chemical peels, and topical creams containing retin A, glycolic acid, and salicylic acid, all of which can increase your risk of sunburn. If you must use an acne-taming product, make sure it’s a cleanser, which is less intense than creams because it spends less time on your skin, according to Dr. Rokhsar.

The bottom line is that your skin is no good at protecting itself — and a pre-tan will only worsen the blow when you finally step foot in real sun.