Even though the long hot days of summer have passed, there is still risk for sun damage to the skin.

Some people believe part of summer is being out in the sun, but a tan is actually evidence of skin damage, said Janis Stone, professor in textiles and clothing.

There is no such thing as a “safe tan,” Stone said, because exposure to the sun can lead to skin cancer.

There are several ways to protect the skin from the sun, Stone said, including staying in the shade, wearing clothing, and using sunscreen.

Stone said covering your skin helps prevent overexposure to the ultraviolet light of the sun. The amount of protection a fabric gives depends on the weight of the fabric, the closeness of the weave or knit, fiber content and color, she said. All these factors can determine a fabrics ultraviolet protective factor (UPF), she said.

The American Society for Testing and Materials (ASTM) issued some guidelines for UPF. The ASTM created a rating system similar to the SPF factor on a bottle of sunscreen. The higher the number, the better protection you will receive, Stone said.

Usually, the darker the fabric, the higher the UPF, Stone said. Thicker and tighter woven fabrics, such as denim, provide more protection than looser knit fabrics, such as T-shirts, she said.

Stone said a person has to use common sense while in the sun because heavier and darker clothes may be warmer and block more of the harmful rays of the sun. There are trade-offs between sun safety and the risk of heat stroke, especially in the summer.

When clothes are labeled with their UPF, consumers can judge how much protection they will provide, Stone said.

Most manufacturers currently do not rate their clothes with UPF because this rating system has only been recently introduced. Fashions are rapidly changing and the necessary testing to determine fabric UPF will be more time-consuming and expensive for manufacturers, Stone said.

Stone said the UPF of clothing can be improved with the use of whitening and brightening laundry detergents. The whitener and brightener is a colorless dye that binds to the fabric and helps absorb ultraviolet light, Stone said.

A hat should also be part of outdoor attire, Stone said. A good hat should shade the face, ears, neck and head, with wide brims working better than baseball caps.

Staying in the shade or inside is another good way of being protected from the sun, especially between the hours of 10 a.m. and 4 p.m. when the rays are the strongest, Stone said.

A person has to be careful because not all shade is good protection. A cloudy day does not protect from the sun, Stone said. The ultraviolet rays pass right through the clouds, and the rays can be reflected off buildings, sand, snow and water, Stone said.

Applying sunscreen is a basic step in skin protection, especially skin that cannot be covered, Stone said. Sunscreen with SPFs of 15 or higher should be used, depending on the individual’s skin type.

Those who cannot help to avoid the sun because of their daily activities or jobs need to be careful and try to avoid overexposure to the sun, Stone said.

Overexposure to the sun is a cause of skin cancer. Skin cancer rates have been increasing at a rate of three percent each year since 1981 and are continuing to rise, Stone said.

According to the Environmental Health Center Web site, www.nsc.org/ehc/sunsafe.htm, skin cancer claimed the lives of about 9,800 people. The Environment Health Center said ultraviolet rays not only cause skin cancer but can also cause cataracts.