Only certain kinds of sun rays are capable of tanning or burning our skin. They're called ultraviolet rays (UV), and they come in two types. UVB rays are less damaging, because they cannot penetrate beyond the first layer of our skin. But UVA rays do penetrate, not only past the first skin layer, but even through hats and most clothing.
UVA rays can damage your skin and eyes even when it's not sunny: They pass right through the clouds and penetrate your skin. Have you noticed a tan on your left arm where you rest it on the car door while driving? It was probably caused by UVA rays coming through your car's side window. UVA rays can also tan your face, hands, and chest through the windshield of your car, when you are driving into the sun.
The best protection when outside is to avoid the sun altogether between 10:00 a.m. and 4:00 p.m., when the sun’s rays are more direct. But those are the very hours when travelers are most often involved with sightseeing and outdoor activities. Here are some tips for protecting your skin on the days when activities keep you out in the sun:
- If you have a history of skin Cancer or sunburn easily, wear clothing that is labeled as sun-protective. Such clothing carries a UPF, or ultraviolet protection factor rating. For example, a UPF rating of 50 means that the clothing will block 98% of the sun's UVA radiation.
- Children should wear sunscreen, but also play in the shade.
- Even if you have normal skin, take advantage of shade from trees, buildings, etc. whenever possible.
- Wear wide-brimmed hats to shade your face and neck.
- Wear sunglasses with a UV rating to protect your eyes from UV damage.
- Use sunscreen that protects the skin, itself, from both UVB and UVA rays.