Mercury Launch

A floppy sun hat and SPF 30 sunscreen just isn’t going to cut it this week, as triple-digit temperatures roll into Southern California and stay--like unwelcome guests--for at least 10 days.

Weather forecasters are calling for near record temperatures in the San Fernando Valley for days to come, and warn the heat might reach dangerous levels in Palm Springs and other desert areas. The mercury in Death Valley is expected to hit 123 degrees today.

But wait--there’s more. Seeking refuge in a nice shady spot may provide a cool respite, but the shade offers scant protection from the sun’s dangerous ultraviolet rays, the primary cause of skin cancer and sunburn, according to a researcher at Purdue University in Indiana.

Instead of shining down in a straight line, ultraviolet B rays bounce around the atmosphere, allowing them to sneak under trees, beach umbrellas and onto the front porch, concluded a study by Richard Grant, an agronomist who conducted the research with Gordon Heisler of the U.S. Forest Service.

Grant, who published his findings in an international scientific journal and made a presentation at a conference of photobiolgists in Utah this week, said the concentration of ultraviolet rays people are exposed to has little to do with the amount of visible light they see. Exposure correlates more to how much open sky people can see from their shady vantage point. The more the sky is obstructed by buildings or trees, the less exposure, he said, but simply relaxing in the one shady spot in an otherwise sunny area is little protection.

Van and Kathy Harter of North Hollywood spent time Tuesday afternoon under a tree at Lake Balboa in Encino, as they watched their three children play in the bright sunshine near the water’s edge.

Van Harter said he is acutely aware of the damage the sun’s rays can do to unprotected skin. “My [uncle] has skin cancer. It started on his nose and then spread. It hasn’t done well by him at all.”

Before leaving for the lake, Kathy Harter took time to slather her brood in No. 23 sunscreen, one of the best ways to protect children from the harmful UV rays--even when they are in the shade, Grant has said.

The Harters would be wise to keep the sunscreen handy. The San Fernando Valley “is going to be baking” starting Thursday, said Gary Ryan, a meteorologist with the National Weather Service in Oxnard.

“I imagine there will be lots of traffic, because every person who lives inland from the beach will be heading to the beach. That’s the only place you’re going to get relief,” Ryan said.

A nice sea breeze is expected to keep the coastal areas in the 70s or 80s, but the cooler temperatures will drift only 15 miles inland--leaving downtown Los Angeles and the Valley sweltering.

The temperature in Woodland Hills is expected to hit 104 degrees Thursday, and creep even higher during the weekend. Expect the same in Burbank and Chatsworth. Downtown Los Angeles will be a tad cooler at 100 degrees, but Palm Springs will climb to about 108, Ryan said.

The scorching temperatures come courtesy of a massive high pressure system blanketing the Southwest, a weather system expected to roost for at least 10 days, Ryan said. After Sunday, temperatures may dip a few degrees to provide some relief.

“You’re talking about some of the highest summer temperatures certainly in the last two years,” said James Murakami, staff meteorologist with UCLA’s atmospheric sciences department.

“There’s always a possibility it may not pan out, but don’t count on it.”

That’s certainly what they’re hoping for at the Calabasas Inn, which has outdoor garden weddings booked all weekend.

“We tell the brides not to worry, that they have to wait until the morning of their wedding day to know what the weather really will be like,” said owner Jean Hollenstein.

If that morning comes, and it’s broiling, the inn breaks out the ice water and umbrellas, she said. And, if need be, the bride can move the whole show indoors.

Brides aren’t the only ones whose blood pressure will rise with the thermometer.

The 10-man crew at Phillip Yee Air Conditioning in downtown Los Angeles has been scrambling across the city all week, as overheated homeowners call in for emergency repairs.

“People have been real cranky,” said Trisha Layman, who answers the phones. “People always wait until the last minute. It’s like this every summer.”

As manager of the Northridge Pool on Reseda Boulevard, Gareth Burke is making sure lifeguards protect themselves from the hazards of the sun--part of a normal day’s work.

The lifeguards put on wide-brimmed straw hats, T-shirts and “gobs” of sunscreen before they sit under an umbrella perched atop the lifeguard chair, Burke said.

“We take the same precautions whether we are sitting in the shade of the umbrella or walking on the deck,” he said. Lifeguards are regularly examined by physicians looking for signs of skin cancer, he said.

One of the few potential benefits of the blistering heat may be a drop in smog levels, said Bruce Selick, meteorologist with the South Coast Air Quality Management District.

When the temperature climbs to about 100 degrees, the heat “punches a hole” in the atmospheric layer above the city, allowing the pollution to dissipate into the upper atmosphere, he said.

“Visibility increases and the smog escapes,” Selick said.

The air, while hot, will be healthier to breathe, he said.

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Keeping Cool as Valley Sizzles

With weather forecasters predicting triple-digit temperatures for the next several days in the San Fernando Valley, heat-related maladies become an all-too-real threat. Below is a guide to recognizing the symptoms of serious conditions and taking first-aid measures. Also listed are tips for avoiding overheating.

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Heat dangers

Heat cramps: Usually affect the legs and/or abdomen. Can signal the early stages of more serious heat-related injuries. Resting in a cool area, drinking cool fluids and massaging the cramped area is often enough to counter the symptoms.

Heat exhaustion: Marked by headaches, nausea, dizziness or fatigue. Treatment is the same as for heat cramps but should be administered promptly to avoid mild shock or heatstroke.

Heatstroke: When left untreated, heatstroke can be fatal as the body, overwhelmed by fatigue, begins to stop high body temperatures, red or dry skin, progressive loss of consciousness, rapid or weak pulse, shallow breathing and vomiting. Seek emergency care immediately.

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Tips for staying cool

* Drink plenty of water.

* Wear lightweight, light-colored clothing.

* Try to avoid going outside between 10 a.m. and 3 p.m. when the rays of the sun are strongest.

* Use sunscreen when outside during the day, even if conditions are cloudy.

* Wear a hat with a brim.

* Eat small meals throughout the day.

* Avoid foods high in protein, which increase metabolic heat.

* Skip alcoholic and caffeinated beverages.

* Avoid using salt tablets unless told to do so by a doctor.

* Work out in the early mornings or evenings. On very hot days, exercise indoors.

Source: American Cancer Society, American Academy of Dermatology, Wellness Encyclopedia