As warm weather approaches, Dr. Reshma Haugen cautions against the dangers of sun exposure.

When summer finally arrives, there’s nothing like the great outdoors. But too much fun in the sun can damage your skin—and putmyou at risk for skin cancer. NorthShore dermatologist Reshma Haugen, MD, on faculty at the University of Chicago Pritzker School of Medicine, answers commonly asked questions about sun exposure and skin cancer.

Q: How does sun damage the skin?
A: Sunlight induces mutations in our skin cells, and over time they may continue to change and become cancerous. Commonly exposed surfaces on the face, ears, neck and upper chest, scalp, hands and arms are areas where skin cancer from the sun typically develops.

Q: Is sun exposure the only cause of skin cancer?
A: No. Some other risk factors include a family history, “immunosuppression” (patients whose immune systems are weakened because of an organ transplant, another type of cancer or immunosuppressive medications), radiation exposure, scarring or having many atypical moles.

But the most common forms of skin cancer—nonmelanoma cancers called basal cell and squamous cell carcinomas—are strongly related to sun exposure. Melanoma, the most serious type of skin cancer, is also associated with high-intensity sun exposure and a history of sunburns.

Q: Are some people more at risk than others?
A: Yes. Redheaded and fair-skinned individuals are at increased risk. People who have had significant sun exposure over a long period of time are also at risk. Recently, we have found more melanoma cases in younger patients, which could be related to their use of tanning beds.

Q: What are the symptoms of skin cancer?
A: There are several warning signs, including a sore or bump that does not heal or continues to scab, flake or bleed. Some skin cancers look like a pink scaly patch or a mole that changes size, shape or color. It’s a good idea to do a skin self-exam every month and check for any changes that may need medical attention.

Q: How can I best protect myself?
A: The best way to prevent skin cancer is to:

• Avoid midday sun, from 10 a.m. to 4 p.m.
• Wear protective clothing, wide-brimmed hats and sunglasses.
• Regularly apply sunscreen.

Q: What types of sunscreen are the most effective and how should they be applied?
A: We suggest sunscreen with an SPF (sun protection factor) of 30 or higher that has ultraviolet, or UVA and UVB, coverage. Follow directions for the recommended amount; most people apply only half as much as indicated. Apply sunscreen to the entire body 15 to 30 minutes before you go outside, paying special attention to the face, ears, back of the neck and hands. Reapply every two hours and after swimming or vigorous activity. Even on cloudy days, UV radiation reaches the surface of the Earth, so also be sure to use sunscreen on these days.