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Preventing Heat & Sun-related illnesses

    "Sunshine on my shoulders...makes me wrinkled"   

Each year, thousands of San Diegans, 'Zonies, and other tourists take full advantage of the local sunshine to either romp or vegetate under the sun. Even "natives", however, often fail to appreciate that San Diego is, in actuality, a desert (albeit an irrigated one) and this poses some definite risks to sun worshippers. In this issue, we'll discuss some tips on safety in the heat.

The sun is a source of different types of energies, particularly heat and light, each associated with their own potential problems for us mere mortals.  

Light can be broken down into "spectrums" or groups of various wavelengths, some of which we can see (so-called "visible light" e.g. colors of the rainbow) and some which we cannot (e.g. x-rays, ultraviolet, etc.). Ultraviolet light can be further subdivided into frequencies that we term ultraviolet A ( UVA) and ultraviolet B (UVB). UVB is the one that has gotten most of the attention over the past years because it is the primary reason for sunburn reactions, while UVA is being more recognized as important to the wrinkling /aging process.

Although the use of sunscreens is finally reaching acceptance, up until the few years or so, commercially available sunscreens only offered protection against UVB and not UVA. Still, any protection was better than none - especially with regards to the prevention of the various skin cancers such as basal cell carcinoma and malignant melanomas. The newer sunscreens (such as Photoplex), fortunately, do offer protection against both UVA and UVB rays. 

Be sure to select a sunscreen/sun block that has a SPF (sun protection factor) of at least 15. Note that this does not represent an absolute number of minutes that you can spend in the sun. Rather, it is a relative number - you can stay out 15 times as long with an SPF of 15, than you can with an SPF of 1, before your skin burns.  For example, if you can stay out only 10 minutes using a sun block SPF 1 before burning, than you can stay out approximately 150 minutes using one with an SPF 15.  Bear in mind that there are other factors to consider as well. You should try to avoid the most intense of the sun's rays in the afternoon - sun block will offer longer protection earlier or later in the day when the sun is not directly overhead. Also, be sure to apply enough sunscreen to do the job properly - most people do not apply adequate amounts - and to reapply as often as needed, especially after swimming or prolonged sweating.

TIP: Get in the habit of applying sunscreen, at least to your face, every morning when you brush your teeth. Be sure to include the back of the neck and ears, as well. (If you drive for a living, consider applying sunscreen to your left/window arm too!)  In the long run, sun screening will not only extend protection against skin cancers, but will help to decrease the amount of wrinkling as you age!

Speaking of sweating, this is just one of the ways that your body cools itself down to avoid overheating. Overheating of your brain leads to all sorts of "nice" conditions ranging from simple heat intolerance to the life threatening heat stroke.

Prevention is the key to the treatment of heat-related illnesses. You can avoid the excitement of receiving intravenous fluids and ice water baths with just a bit of forethought. The key here is adequate hydration prior to your activities and maintaining it through their duration. This applies whether you are sunbathing on the beach or playing a few hard sets of volleyball (the only difference may be in the amount of fluid needed to be consumed).

You should ideally begin the day before by drinking as much of your favorite fluid (not alcohol!) as you can tolerate (you'll know you've had enough when your pee is clear!). Then, before your "event", drink two 8 ounce glasses of fluid approximately 20 minutes prior to the start. As the game or activity continues, you should plan on drinking 8 ounces of fluid about every 20 minutes or so, depending upon the activity and your intensity, until you finish. If you're feeling fatigued, increase your fluid intake.

What is the ideal replacement fluid? For activities lasting less than one hour, there is no benefit to anything more expensive than plain water. Activities lasting longer and associated with heavy or steady loss of body fluids through sweat and dehydration may benefit from one of the commercially available rehydration solutions (e.g. Gatorade, Exceed, etc.) which contain electrolytes (sodium, potassium) and 4-6% sugar for calories. (Regular fruit juice has a sugar concentration that is too high for replacement in an athletic event and this will slow emptying of the stomach. Diluting it by half with water, however, is a reasonable alternative.) Experiment with the various brands to see which one tastes best to you (read: most tolerable) and stick with the one with which you feel the most comfortable.

Alcohol can lead to further dehydration, therefore, itís best avoided!

Don't forget to increase your salt intake under hot weather conditions (unless your doctor has told you otherwise), along with your fluid consumption.

Rationale:

Most of us have had it well-drilled into our heads about the importance of drinking plenty of fluids in order to avoid dehydration under these circumstances. However, it's possible to run into other potentially deadly medical problems if one only consumes plain water, particularly lots of it.

Our bodies produce sweat as a cooling mechanism in hot weather. The evaporation of the sweat from off of our bodies is what cools us down. Sweat contains both salt (sodium) and water. Drinking lots of plain water replenishes the fluid losses, but - at the same time - serves to dilute the already diminished sodium stores that remain in the body. This results in a condition known as "hyponatremia."

When the sodium concentration in our blood drops just a little lower than normal, we might feel some nausea, fatigue, and "just don't feel right." If it continues to drop, dizziness develops and this may be accompanied by muscle cramps and vomiting. If the serum sodium drops too low, victims can experience seizures, go into a coma, and even die!

So, how to avoid this problem?

If you're only going to need a few sips of liquid, then water is fine. However, if you need to drink lots of fluid, particularly over a period of greater than 1 1/2 hours, then a better choice of fluid replacement would be one of the electrolyte sports drinks such as Gatorade or Powerade. Be aware that these drinks may not fully replace the lost sodium, either, but they're much better/safer than plain ol' cold water under these circumstances.

Another option: Keep a few of those small salt packets handy (e.g. from your favorite fast food restaurant - no lectures on that today...) and open the contents of one into the palm of your hand and lick all of the salt off. As little as 2 or 3 packets per day can help to maintain the serum sodium level up to where it should be. Also, unless your doctor has cautioned you against this, be more liberal with the use of a salt shaker with your meals under these hot weather conditions.

Does this strategy work? Yes, definitely. This has been a problem that we had noted in our runners for a while, particularly under warm race conditions. (Inexperienced runners tend to believe that they must drink water at every water station.)

Also, we tend to see more high school and college football athletes cramp up during games under hot weather conditions. Somewhere along the way, smart athletic trainers discovered that providing pickle juice to their players helped to cut down on the frequency and intensity of the cramping. (You'll have to trust me that Gatorade or licking salt straight off of your hand tastes a whole lot better than pickle juice.)

What about clothing?

Broad-brimmed hats, long sleeves, and long slacks or skirts offer protection (a baseball cap offers SPF 5 protection for the forehead.) A T-shirt or thin cover-up is probably not very effective, however, especially if itís made of gauzy, loosely-woven material.

***Warning: some medications can cause problems when used in the sun or heat!!!

Certain antibiotics (sulfonamides, doxycycline. etc.), diuretics (furosemide), acne meds (Accutane, Retin A) , as well as some soaps and perfumes can cause a photosensitivity reaction in some people. This may occur as an exaggerated sunburn or rash on an exposed area.

Also, individuals taking certain antipsychotic medications such as Thorazine and Haldol can develop a malignant hyperthermia syndrome and die from it. Consult your physician if you have any questions/concerns!

Jeffrey Pearson, D.O. (1995)

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