There's little evidence to support the idea that a base tan protects you against sunburn. A few sessions of indoor tanning will not prevent you from burning in the sun. A base tan is no substitute for good sun protection. Plus, the risks of long-term tanning outweigh the unproven benefits of a base tan.

Tanning under the sun or a sunlamp may give modest protection to those who are able to tan well. But the protection it gives does not come close to that derived from the use of a sunscreen. The larger issue is that any change in skin color from tanning is a sign of damage from ultraviolet (UV) radiation. Repeated exposure to UV radiation — whether from the sun or a tanning bed — increases your risk of premature skin aging and skin cancer.

Use these methods to prevent sunburn and other skin conditions:

• Avoid sun exposure between 10 a.m. and 4 p.m. The sun's rays are strongest during these hours.
• Cover up. While outside, wear tightly woven clothing that covers your arms and legs. Consider wearing clothing specially designed to provide sun protection. A broad-brimmed hat and sunglasses with a high UV protection rating also will help.

• Use sunscreen frequently and liberally. Apply a broad-spectrum sunscreen with a sun protection factor (SPF) of at least 15. The American Academy of Dermatology recommends using a broad-spectrum, water-resistant sunscreen with an SPF of at least 30.

  Apply sunscreen 15 to 30 minutes before going outside. And reapply it every two hours — or more often if you're swimming or perspiring.

  Some people have medical conditions that may require a few short exposures to UV light before summer or a sunny vacation, to prevent flare-ups. Talk with your doctor before doing this.