It’s also helpful to know which sun protection aids on the market measure up to their claims. Following are a few products and procedures you may have heard about.

Some companies promote ingestible pills that purport to provide sun protection. Experts say there is insufficient scientific evidence to support these claims.

There are bracelets that manufacturers claim will signal you when it’s time to apply more sunscreen or to move into the shade. Experts don’t consider these an adequate safeguard.

While some companies claim their contact lenses protect your eyes from ultraviolet rays, this is a little misleading since the entire eyeball needs protection. For best results, use a pair of comfortable wraparound sunglasses with an ultraviolet block and polarizing lenses.

Cellulose fabrics, like acetate and rayon, block some ultraviolet rays. Rit makes a product called SunGuard, a detergent you add into your washer, that significantly improves the sun protection factor of cotton clothes for about 20 washings.

For maximum safety, look for some combination of these ingredients in a sunscreen: avobenzone, mexoryl, oxybenzone, titanium dioxide, and zinc oxide.

Your car windows are already protecting you from 50–75 percent of the sun’s rays. Film that rejects as much as 99 percent of ultraviolet rays can be applied to windows. Have this done professionally, however, as the do-it-yourself products are very difficult to apply effectively and often bubble. Many states govern how much you can tint certain car windows, such as the windshield and driver’s side front window. A window-tinting professional can provide guidance on this.