You may not want to hear this, but there’s no such thing as a “healthy” tan. Tan skin is actually a sign of skin damage from ultraviolet rays, which can trigger changes in the DNA of your skin cells. Most of the time your immune system can repair these DNA mutations, but occasionally some are missed and these can turn into skin cancer.

Those who have fair to light skin and children are especially vulnerable to skin damage from too much sun. In fact, everyone should wear sunscreen or protective clothing when outdoors and also limit their time in the sun when the sun’s rays are the strongest — between 10 a.m. and 2 p.m.

Unfortunately, every doctor knows that some of you just won’t be able to resist having that “sun-kissed” look for the summer, but please be sure to get it while wearing plenty of sunscreen to help minimize the damage to your skin. Also, even if you choose not to wear sunscreen, please use it on your kids.

Here’s what you need to know about the sun’s rays and how to choose and apply the right sunscreen for yourself and each of your family members.

What are UV rays?

Exposure to ultraviolet (UV) rays is the most important preventable risk factor for skin cancer. Skin damage from UV rays early in life can lead to skin cancer later in life. Sunscreen plays an important role in blocking the absorption of UV radiation by the skin; however, no sunscreen blocks 100 percent of UV radiation. Sunscreen extends the length of time you can be outdoors before your skin begins to redden, but it doesn't give you total protection. Using sunscreen doesn't mean you can stay out in the sun indefinitely, since damage is still occurring.

Keep in mind that automobile glass doesn’t block UV rays. People who drive in the sun should also use sunscreen to avoid sun damage to their skin, as well as their eyes.

What does SPF mean?

The sun protection factor (SPF) on a sunscreen label is a measure of how well the sunscreen protects against ultraviolet B (UVB) rays. UVB rays are the main cause of sunburns, but like ultraviolet A (UVA) rays, they can also contribute to skin cancer. The SPF on a label does not say anything about a sunscreen's ability to block UVA rays.

Higher SPF numbers mean greater protection from UVB rays, but no sunscreen can block all UVB rays. For example, a sunscreen with an SPF of 30 blocks about 97 percent of UVB rays, while a sunscreen with an SPF of 50 blocks about 98 percent of UVB rays.

How to select a sunscreen

Choose a sunscreen that offers:

Broad-spectrum protection (protects against both UVA and UVB rays)

• An SPF of 30 or higher
• Water resistance (protection while swimming or sweating for a specified time)
• What is the best type or brand of sunscreen? Any one you will use again and again — provided that it meets the criteria above. Available options include lotions, creams, gels, sticks and sprays, so there are plenty of options.

How to apply sunscreen

Most people do not apply enough sunscreen or apply it properly. You should:

• Apply sunscreen to all areas of skin not covered by clothing.
• Use at least an ounce of sunscreen to cover exposed areas, and adjust the amount depending on your body size.
• Apply the sunscreen to dry skin about 15 minutes before going outdoors to give it time to be absorbed, and use waterproof sunscreen if you will be swimming.
• Reapply sunscreen at least every two hours — more often when swimming or sweating.
• Protect your lips by applying a lip balm or lipstick that contains sunscreen with an SPF of 30 or higher.

Children especially need protection from the sun. Sunscreen is recommended for everyone older than 6 months of age. For babies younger than 6 months, only use sunscreen if adequate, lightweight clothing that completely covers the infant and shade are not available. Apply a minimal amount of sunscreen to exposed areas, such as the baby's face and the back of his or her hands.

Don't rely solely on sunscreen

Using sunscreen when you are going out in the sun is important, but other important strategies to protect your skin include: seeking shade, wearing a hat (and perhaps even long sleeves and pants), and avoiding tanning beds and sunlamps.

Learn more about Sun Safety in Tanner’s Health Library.