HEAT WAVE KICKS INTO HIGH GEAR.

Byline: Dana Bartholomew Staff Writer

PACOIMA - It was bad enough that nine men at J.C. Welding work with blue torches dangling from their forearms.

But as mercury readings hovered around 100 degrees Monday, some said a predicted San Fernando Valley heat wave this week could send hellfire through their souls.

``Of course, we're hot,'' foreman Miguel Rublcaba said amid the burning acetylene and molten metal. ``Drinking a lot of water - what else can you do?

``Either that or we drop dead.''

Triple-digit temperatures forecast for the San Fernando Valley have already sent residents scurrying for their Big Gulps, sun umbrellas and cool relief.

Meteorologists say temperatures expected to hit 105 degrees through Thursday could mark the first heat wave of the summer - and break records following the driest season in Los Angeles history.

``It looks like this may last five days,'' said Bruce Rockwell, a meteorologist with the National Weather Service in Oxnard. ``It looks like there might be some records broken in the Valley.''

A high-pressure zone from the Great Basin desert has stymied summer sea breezes that normally make Valley patios comfortable. Temperatures are expected to cool to the high 80s to 100 Friday and Saturday, and into the mid-90s Sunday and Monday.

On Monday, temperatures hit 94 in Burbank, 90 in Glendale, 99 in Van Nuys, 105 in Woodland Hills, 101 in Chatsworth, 103 in Lancaster, 95 in Simi Valley, 93 in Thousand Oaks and 97 in Newhall, and 83 in downtown Los Angeles.

Air quality officials reported good to healthy air in the South Coast Air Basin, with moderate to unhealthful air forecast for today. Air and health officials warned that active children and adults and those with respiratory diseases such as asthma should avoid prolonged outdoor exertion and use extreme caution.

``Extreme heat can be very dangerous for seniors, children and others whose immune and respiratory systems are not working properly,'' said Dr. James Haughton, medical director for the Los Angeles County Department of Health Services, in a statement.

``Even if you are in good health, exertion without the proper amount of fluids and rest can be harmful.''

The heat especially worries fire officials concerned about extreme fire danger after the driest season for Los Angeles in 30 years.

Fuel moisture in the San Gabriel Mountains has already dropped to between 8 percent and 9 percent - an incendiary nightmare for firefighters, according to forestry officials.

``The hotter the temperatures, the more moisture we lose,'' said Bob Brady, spokesman for the U.S. Forest Service's Pacific Southwest Region. ``Brush becomes explosive in fire if less than 15 percent - so we're already in explosive conditions.''

Across the Valley on Monday, residents sought relief. Some doffed shirts. Others donned sunbonnets. Many just simply plodded through their workday.

At ``Cadillac Jack's'' - a 1950s Pacoima diner without air conditioning - dozens of rock-video extras of the alternative band Homegrown packed shoulder to shoulder as they waited for the cameras to roll.

``Oh, man, it's cooking in there,'' exclaimed Manny Jiminez, a video grip sweating before a sunlike floodlight. ``Just where we wanted to be at the beginning of a heat wave - everybody's mopping.''

At Iceon Skating Center in Sylmar, a dozen hockey players found relief atop the dusty rink.

``It's real cool, good to be here instead of out there,'' said Jason Moore, 12, of Sylmar, between scrimmages. ``I like to come in here even when there's no hockey games.''