By William Lide, M.D.

There are fewer places in the world more seductive than Pleasanton during the spring and summer. And a life of total health includes enjoying as many hours outside as you can. But living a life of total health also requires that you take some simple and inexpensive precautions to prevent injury from some of the dangers that outdoor activities can present.

First, when going out in direct sunlight, there are several steps you should take to protect yourself from harmful ultraviolet (UV) rays. Sunscreen plays a key role in skin protection, but there are other precautions equally as important.

For example, whenever possible, schedule outdoor activities before 10 a.m., or after 4 p.m. The time between these hours is when the sun is likely to do the most damage. Use your shadow as a measure. If it's shorter than your height, it's time to exercise more caution and protect yourself from extended exposure. If it's longer, you can be exposed for longer periods of time.

Seek the shade. When you are outside, find the trees, or other cool, shady spots—anywhere that doesn't directly expose your skin to the sun. This is a good method to use for picnics, or any activities where you might be outside for several hours.

If you're going to be in direct sunlight, it is essential to wear hats and other protective clothing.  Find a hat that has ventilation and a full brim, to protect your head, face and neck. There are many shirts on the market vented for coolness, and designed for sun protection. T-shirts don't always offer the best protection, especially when they're brand new, and when they get wet.  

Finally, use sunscreen, but make sure to use enough. Apply at least two tablespoons to cover your face, arms and legs.; less than that will provide some protection, but not as much as you may be expecting. Try to re-apply sunscreen every two hours or so, as the chemicals will break down over time, when they get wet, etc.

Don't be fooled by the sun protection factor (SPF) number that sunscreen makers use to rate the amount of protection you receive. A product with an spf factor of 100 doesn't provide 70 percent more protection than a product with an spf of 30. You get a little more protection, but for most uses, an spf of 30 is sufficient. Just remember to reapply it every two or so hours.

Also, make sure your sunscreen has an ingredient called avobenzene. This helps filter out the UVA rays, which assist in tanning, but also in skin aging and cancer. This is the most common and least expensive chemical to use to help filter out UVA rays.

There is, of course, no substitute for common sense, so make sure to wear protective gear when cycling, skating or climbing. Don't go hiking or swimming alone, and make sure to take a GPS device or accurate maps if you're heading out into unknown wilderness areas.

If you are leaving the area or state entirely, it's a good idea to take along a copy of your medical record should an emergency arise. Your doctor can help you with that. Kaiser Permanente now offers a portable electronic medical record on a secure, password-protected flash drive. If you're a member of Kaiser Permanente, see your personal physician for details.

And for everyone this year, have a delightful, and safe, season in the sun.

Dr. William Lide is a dermatologist with Kaiser Permanente, Pleasanton