First there was binge drinking – now there’s binge tanning. That’s when you cram in a lot of tanning before a big event, like the prom, or while you’re on vacation.

People may think it’s no big deal to fry themselves on vacation once a year, but doctors say “sporadic yet intense” UV exposure, or binge tanning, is quote, “an extreme assault to our DNA.” That’s according to Dr. Susan Swetter, a professor of dermatology at the Stanford Cancer Institute. She says, binge tanning triggers harmful changes in cells that result in the most fatal form of skin cancer – melanoma. And the damage keeps accumulating.

So, if you go on a once-a-year vacay to Cabo, and fry yourself in the sun each time, that increases your risk of skin cancer each and every time. Lie in a tanning bed once-a-day, the week before a big event – like your high school reunion – and your risk of basal cell carcinoma increases by nearly 75 percent just from that one week. And that’s the most common type of skin cancer.

But they’re just as dangerous – if not worse. That’s because they’re designed to get you tanned more quickly than the same amount of time in the sun. In fact, compared to the noonday sun, bulbs in tanning beds emit twelve times as many UVA rays, and twice as many UVB rays.

That’s why doctors say binge-tanning behavior is a big factor in the 800 percent increase in diagnoses of deadly melanoma over the last few decades. Bottom line: Think of binge tanning like this. If someone decided to smoke a carton of cigarettes at once – instead of just smoking a pack a day – we wouldn’t be surprised if they had a lot of health problems. That’s the same with binge tanning.