The most obvious danger that anyone faces when they work outdoors is that of the sun.

Lifeguards are no different. Surprisingly, many people are not aware of the many negative effects the sun has on the body. Here are the major ones, along with some solutions for prevention.

1. Heat exhaustion - Dehydration caused when the body loses too much salt and fluid through sweat. One of the most serious side effects of sun exposure. Get out of the heat and drink fluids.

2. Heatstroke - Much more dangerous than heat exhaustion, the body's heat-control system actually shuts down. Body temperature can rise as high as 110 degrees F. People with heatstroke may have very dry skin, unconsciousness, high fevers, confusion, and may eventually experience the heart, nervous system, kidneys, and liver. They need to go directly to the emergency room.

3. Skin damage - Not only does sun inhibit the immune system and cause early skin aging, but it can also cause skin cancer that develops long after your exposure. The damage is caused by UVA and UVB ultraviolet rays. Although both are harmful, UVB is the main culprit of skin cancer. They are absorbed by and then can deform DNA, causing uncontrolled division, and consequently, cancer. Use a sunscreen with at least SPF 15 and apply it at least 15 minutes before going outside. Also, continually reapply the product when needed. Young people are especially at risk, we get 75% of our sun exposure before we are 18. (Robert Polisky, M.D., board-certified dermatologist on staff at Alexian Brothers Medical Center, Elk Grove Village, Illinois)

4. Melanoma - The most serious type of skin cancer, it's usually fatal. It affects anyone, although light skinned, light haired people are at highest risk. Light eyes, sunburns, and freckles also increase risk significantly. One severe sunburn early in life can greatly increase the risk of melanoma. Melanoma can also be prevented using an SPF 15 lotion, although lifeguards are often seen with zinc oxide, which can now be obtained in clear form. This type of sunscreen is actually better due to the fact that it's a physical barrier from the sun, like shade, not a chemical one. Moles can be a sign of melanoma. A way to identify cancerous moles is through the ABCD method: Asymmetry - is it round?

Border - are the edges uniform?

Color - is it all the same?

Diameter - is it fairly small and constant in size?

If you answer no to any of those questions, you may have melanoma.

Obviously the sun is not to be taken lightly! There is a lot more exposure due to ozone depletion, and sunscreen gives people an excuse to spend more time in the sun. In general, try to stay in the shade (especially between 10 am and 3 pm)

, wear appropriate clothing and use sunscreen properly. You can't avoid the sun but at least protect yourself from it.