A: Vanessa, you’re right that special clothing to protect children from the sun has become more popular. And this is a very good trend. Over recent years, we have become more aware of the dangers of the sun’s ultraviolet rays (UVA and UVB) in causing skin damage and skin cancer. We have also recognized the importance of protecting children’s skin, since most of our lifetime exposure to sun occurs during childhood. Studies have shown that blistering sunburns in childhood can significantly raise the risk of developing skin cancer later in life.

The American Cancer Society recommends avoiding sun exposure by staying indoors during the midday hours, playing in the shade and taking the following measures:

• Slip on a shirt. Wear protective clothing when out in the sun.
• Slop on sunscreen with an SPF of 15 or higher.
• Slap on a hat that shades the face, neck and ears.

Sun protective clothing has been popular in Australia for more than a decade and is finally catching on in the United States. There are many manufacturers of sun protective clothing. Look for a tag from the American Society for Testing and Materials (ASTM) that certifies the Ultraviolet Protection Factor (UPF) rating. If it says “UPF 50+” this means that the fabric blocks 98 percent of the UV rays. You can compare this to sunblock cream, which is recommended at Sun Protection Factor (SPF) of 15 or above, blocking at least 93 percent of the UV rays. However, fabric has the additional value over sunblock of not washing off and needing to be reapplied after swimming.

Although regular T-shirts can provide sufficient sun protection, most do not. Studies found that most regular summer clothing rated below SPF 30, and typical white T-shirts offered the equivalent of SPF 10 when dry and virtually no protection when wet. The best sun protection is provided by heavier, tighter weave, less stretchy, and dark colored fabrics—exactly the opposite of what most people choose to wear in the summer, since they’re hotter.

The specially manufactured sun protective clothing uses synthetic, tightly woven fabrics often with chemical treatments to absorb or diffuse UV rays, allowing them to block the rays while being lightweight, breathable and comfortable in the heat. There is colorful one-piece and two-piece children’s swimwear that covers their bodies to their elbows and knees. If you use regular T-shirts to cover up, choose darker and tighter-weave fabrics that you cannot see through. For added protection, you can add a chemical product called SunGuard to the laundry, which gives clothes an SPF of 30 for up to 20 washes.