On a warm May afternoon, I was spending the day with my mom, soaking up some early-summer rays next to a local reservoir, when she touched my arm and asked, “Have you gotten this checked out?” She was pointing to a mole. At first glance, it looked innocuous—round and only the size of a watermelon seed—but it had some odd features. It was pink and dotted with a few tiny white pinpricks, totally different in appearance from my thousands of other moles and freckles. 

I was 22 years old, fresh out of college, and totally absorbed in my preparation for a two-month-long bike tour. Still, I went ahead and got a biopsy. A few days later, I received a call. It was melanoma, the most dangerous form of skin cancer. 

Melanoma diagnoses have steadily grown more common over the past two decades—and people like me (those younger than 40 years of age) are among those receiving them. When caught in the early stages, it is easily treated and has a five-year survival rate of 99 percent. I was fortunate enough to fall into that camp. A few days after my diagnosis, I had 16 stitches, and no cancer. If I’d left on my trip without getting it treated, my doctor informed me, it might have started to spread throughout my body. Once melanoma metastasizes, the odds of still being alive five years after diagnosis drops to 30 percent.

Melanoma is particularly common among people who, like me, love to spend their weekends and summers outdoors—trail running, lake swimming, road cycling, and general adventuring. Is it possible to prevent this disease without becoming a hermit? According to Elizabeth Berry, a dermatologist at Oregon Health and Sciences University, the answer is "absolutely.” Here’s how.

Understand the risks

Like most cancers, melanoma becomes more common as you get older. Not only do aging cells accumulate more mutations that have the potential to cause cancer, but the immune system becomes worse at attacking cancer cells. 

That said, it’s a misconception that young people don’t get this cancer. “Some of the worst melanomas I see are in young people,” Berry said. In fact, it’s one of the most common, and deadliest, cancers among teens and young adults. 

Then there’s your skin tone. White people are 30 times more likely to develop melanoma than Black or Hispanic people, according to the American Academy of Dermatology Association. However, darker-skinned people still need to be cautious about sun exposure and keep an eye out for unusual marks; research suggests that this population is less likely to spot melanoma before it spreads to a life-threatening degree. 

Pay attention to the quality of your sun exposure

I’d always assumed I got melanoma because of my college years in Southern California, when I swam in an outdoor pool nearly every day, stopped wearing sunscreen, and developed a deep tan. 

It’s far more likely that I can trace my melanoma back to all the times, growing up as a pasty Oregonian, I headed out to the lake on the first warm day of the year and came home lobster red. That’s because melanoma is associated with intermittent, severe sun exposure, not the regular, daily kind. Case in point: Oregonians (along with Minnesotans and Vermonters) actually have some of the highest rates of melanoma in the country. “You've got this perfect storm of really outdoorsy people who don't get a whole lot of sun in the winter, then go out without adequate protection in the summer and get these terrible one-hit sunburns,” Berry said. Researchers estimate that for every blistering sunburn you get, your melanoma risk increases another 50 percent. That said, the answer isn’t to start spending every day sunbathing (even if you do tan, regular sun exposure is associated with other kinds of skin cancer, such as basal cell and squamous cell carcinoma). 

Be careful during the sunniest parts of the day

You can strategically plan outings to avoid potentially melanoma-causing sunburns. First, try to plan outdoor activities to avoid between 10 AM and 4 PM, said Ida Orengo, a dermatology professor at Baylor College of Medicine. Plan a sunrise hike or late-afternoon swim rather than an all-day trek or beach day. 

During those sunniest hours, you don’t have to hide indoors, but you do need to be strategic. Seek activities that take you out of the sun. Pick a heavily forested camping spot or mountain bike trail instead of road ride. It’s particularly important to avoid any activities that take place near pavement, water, or snow when the sun is shining directly overhead. These surfaces reflect UV light, giving you a double hit of exposure. Wait for the evening or a day with heavy cloud cover for water sports, road cycling, and spring skiing.

If you do choose to go out during the brightest hours of the day, slap on some sunscreen. And not just a thin layer—if you don’t look like a ghost before the sunscreen soaks in, you’re probably not doing it right. Experts recommend a shot glass’s worth of sunscreen for your whole body. Don’t forget to reapply every two hours. If remembering to reapply sunscreen is tough for you, UV-resistant clothing is an effective substitute—and may even provide more protection, according to a study published earlier this year in the journal Cancers and coauthored by Berry. Most outdoor clothing retailers sell clothes specifically engineered to block the sun's rays, blocking upwards of four times as much UV radiation as regular cotton or polyester. You can also buy chemical solutions that go in with your laundry, rendering your own clothing UV resistant for up to 20 washes. 

Keep a close eye on your skin

Part of what differentiates melanoma from other forms of skin cancer, including basal cell and squamous cell carcinoma, is how fast it grows. One study combed through the National Cancer Database and analyzed survival data from more than 150,000 patients with melanoma. The results, published in the Journal of the American Academy of Dermatology, found that people with stage 1 melanoma who waited three months for treatment after diagnosis had a 29 percent higher risk of death between three and 10 years after diagnosis compared with people who sought treatment right away. This rose to 41 percent among people who waited four months. 

For most people, Orengo recommends a yearly skin check, in which a dermatologist gives your body a thorough scan and biopsies any irregular looking moles and lesions. Because I’m at high risk of developing melanoma a second time, I visit my dermatologist twice a year. In between appointments, I keep an eye out for any moles that have irregular shapes or odd colors, especially those that are unusually dark, pink-looking, or have spots. If I notice a mole that seems to have changed shape, size, or color, I call my dermatologist right away. 

Since my melanoma diagnosis, I have become much less cavalier about the sun—at the beach, you’ll find me hiding in the shade. During the day, I completely avoid road riding and outdoor pools. And when it’s sunny, I constantly sport a ghostlike sheen. But overall, my lifestyle hasn’t changed that much. I still trail run, hike, and camp all summer long. As Berry puts it, “You just have to protect your skin while you’re doing what you love doing.”