TOO DARN HOT BE SMART IN YOUR APPROACH TO SUMMER EXERCISE.

Byline: Jillian O'Connor Staff Writer

Southern California is the land of sunshine, palm trees and low humidity, but a noontime jog in sweltering August temperatures is not likely to make you feel more energetic when the heat spikes to 98 and smog is a dark, stagnant mass framing the Valley.

But who wants to be in an air-conditioned gym, pounding away on a make-believe track or climbing imaginary stairs when there's a chance to hike a canyon or go for a run in the park?

The good news is that with the proper precautions, and plenty of water, healthy adults and teens can pull off outdoor workouts safely in the summer - though experts warn there's always a risk.

``When it's particularly hot and humid, it's a smart idea to limit outside physical activity,'' says Dr. Philip Schwarzman, medical director of the emergency department at Providence St. Joseph Medical Center in Burbank, who recommends the scenery of a nice cool gym.

On a recent summer day, the hospital's emergency room saw a few cases of heat exhaustion, caused by outdoor activities including running and even gardening.

Unfortunately, regular exercisers - whether they're jogging or walking, or playing tennis or basketball - can often fool themselves into thinking they can keep up outdoor regimens when the mercury shoots up.

``A lot of people I know work out in the extreme heat just to build up endurance, but it's not good,'' says certified personal trainer Mark Harari, an instructor at Barry's Bootcamp in Sherman Oaks.

``I would say anything above 90 degrees, you need to start being a little bit careful because you're going to start (to get) dehydrated a little more quickly,'' says Harari, who favors getting up early or heading out late for a run to stay cooler.

``That heat is going to zap your energy faster. And if you're used to running three or four miles, mentally you feel like, 'I can go another two miles,' even though you're getting tired. It's just one of those things people do.''

Preventing dehydration in ballplayers is a major goal of the Dodgers' team physician, Dr. Michael Mellman, who keeps an eye on fluid loss at the baseball team's training sessions by taking athletes' weights before and after exertion.

According to Mellman, who is also the team doctor for the L.A. Kings, weight loss that follows an activity is just water loss, through sweating as well as exhalation.

Water is essential to maintaining performance and staying healthy as it keeps the body's core temperature low.

``The problem often is that people don't get thirsty at the same rate they get dehydrated,'' says Mellman. ``The fluid consumption has to be in anticipation of thirst, as opposed to waiting for thirst.''

Taylor-Kevin Isaacs, a clinical exercise physiologist and private trainer, advises athletes to drink up before, during and after a workout in a regimen consisting of 16 ounces of water two hours before exercise, and again 17 minutes before the session. The exerciser should then drink as much as possible every 17 minutes. After finishing up, another two cups of water is advised.

``Everyone's heard of the DUI,'' says Isaacs. ``People need to start talking about the DWE, which is 'drink while exercising.' ''

According to Isaacs, fluid loss hits the danger zone when a person's body weight after exercise has decreased by 3 percent or more. And in all cases, the weight lost in the course of exercise should be made up for with an equal amount of water after the session. For instance, says Isaacs, a person who has dropped a pound (16 ounces) by sweating during exercise needs to make up for the fluid loss with at least 16 ounces from the water bottle.

Sports drinks, hyped for restoring electrolytes, can be a good option for people competing in a marathon that day, says Isaacs, but he almost always recommends plain old water so exercisers don't load up on unnecessary calories and sugar.

In addition to swigging water regularly, trainer Harari advises ducking out of the burning rays.

``If there's any way, get into some shade while you're jogging - wear a hat,'' says Harari. ``Anything just to keep your body a little bit cooler is going to help dramatically.''

Even when Americans aren't exerting themselves in hot weather, high outdoor heat can cause major medical difficulties. Between 1979 and 1999, 8,015 people died in the United States from heat exposure, and it is not unusual for emergency room doctors to see many cases on a summer day.

The key symptoms, according to ER doctor Schwarzman, are extreme weakness, thirst, fatigue, visual problems, and a lack of sweating, which is a very serious problem. Possible severe outcomes include hallucinations; organ damage including heart attacks; a change in one's mental state; and even death.

Individuals differ in susceptibility to heat exhaustion, and its more severe counterpart, heat stroke. As Dodger doctor Mellman notes, a family history of heat illness can increase the likelihood of a person suffering a bout, as can a history of personal experience with the condition.

Cenk Uygur, a frequent jogger in his 30s who lives in West Hollywood, is a sensible exerciser now, but learned to stop one bad habit after a poor choice nearly led to heat exhaustion.

``I was being foolish when I was younger, and I ran with a sweat shirt on in the middle of summer because I was trying to lose weight before I realized that that was incredibly inane,'' says Uygur, a talk-show host on Sirius satellite radio.

When a patient is indeed suffering heat stroke, treatment is aimed at bringing down the body temperature quickly, often with the aid of ice, cool water and alcohol on the ailing person's skin, according to Dr. Joseph Beezy, a board-certified physician in emergency medicine at Kaiser Permanente Panorama City Medical Center.

The Centers for Disease Control and Prevention recommend avoiding too much exposure at peak sun, which is 10 a.m. to 4 p.m. in the summer, and note that rays affect skin even on hazy or cloudy days.

The instant effects of getting too much sun are sunburn and premature aging, but the long-term risks include skin cancers such as basal and squamous cell carcinomas, as well as the frequently deadly melanoma. A broad-spectrum sunscreen with a minimum of SPF 15 helps stave off sunburn, though overexposure can still ravage the skin.

To stay cool and safe, Carol Argo, an aquatic trainer in Rancho Palos Verdes, favors taking workouts to the pool, and offers submerged versions of yoga, tai chi and Pilates.

``When you're in the water, your body temperature stays down, which is lovely,'' says Argo. ``People don't get hot in the water because the water is significantly lower than body temperature.''

The trainer, who brings some of her lessons to a retirement home, stresses the dangers of exertion in the heat for older adults, a concern that is echoed by Beezy.

Beezy points out that the elderly often have decreased sensitivity to temperature, and that it's crucial in hot weather for caregivers to keep an eye on relatives and neighbors who may not have access to air conditioning or fail to take precautions to beat the intense heat.

Ask ``do you have air conditioning? Is it working? Is it turned on?'' says Beezy, explaining that people not only need to take responsibility for their own health, but look out for others' well-being, too.

And whenever it's hot - whether you're working on a roof, sitting in a yard, training for a marathon or skating at the beach - it can't hurt to recall this bit of advice from Schwarzman: ``If you're feeling thirsty, you're already behind.''

Tips for outdoor summer workouts

-- Be sure to keep plenty of water on hand.

-- Wear a sunscreen with at least SPF 15. Choose one that contains zinc oxide, titanium dioxide or Parsol 1789 (avobenzone) to block UVA rays as well as UVB.

-- Seek shade and wear a hat and sunglasses, which help prevent cataract damage to eyes from sunlight.

-- If you've experienced heat exhaustion or heat stroke before, consider moving the workout to an air-conditioned area indoors.

-- Be aware that certain medications (such as diuretics and some psychoactive drugs) and alcohol increase susceptibility to heat exhaustion.

-- Try to avoid working out during the season's peak sunshine hours, 10 a.m. to 4 p.m.

-- Pay careful attention to water loss by noting weight before and after exercise; replace the weight lost with an equal quantity of water.

-- Avoid sports that require players to wear heavy padded equipment, such as football.

-- To stay cooler, try activities in the water.

-- Take breaks as needed.

-- Pay attention to air-quality warnings, and avoid exercise on days deemed unhealthful. Those with respiratory problems should consult a physician before exercising outdoors in summer.

-- To use a heat index calculator, which factors in heat and humidity to find the temperature the body experiences, go to www.srh.noaa.gov/elp/wxcalc/heatindex.shtm

- Compiled by Jillian O'Connor

CAPTION(S):

2 photos, box

Photo:

(1 -- cover -- color) ON THE COVER: Mark Harari cools off in a sprinkler at Warner Center Park.

(2) ``Heat is going to zap your energy faster,'' says trainer Mark Harari. ``And if you're used to running three or four miles, mentally you feel like, 'I can go another two miles,' even though you're getting tired.''

Tina Burch/Staff Photographer

Box:

Tips for outdoors summer workouts (see text)