Extreme Heat Driving SoCal Wildfire and Safety Concerns

Triple-digit temperatures forecast throughout large swaths of Southern California for the early part of this week are driving extreme heat warnings and wildfire worries.

Monday was expected to be the hottest day, with some relief expected Tuesday and the likely cancellation of a National Weather Service excessive heat warning on Wednesday.

These kinds of high temperatures can cause death, and the National Weather Service is recommending people in the affected area -- all of California south of San Luis Obispo on the coast and Death Valley National Park inland -- stay inside cooled buildings if possible. Parts of southern Arizona and Nevada are also under the warning.

Kathy Hoxsie, meteorologist with the National Weather Service's Los Angeles/Oxnard office, said temperatures this high generally hit in the dead of summer, but a heat wave this time of year isn't unheard of.

"This isn’t a huge outbreak," she said, "but it’s enough to be dangerous if people don’t stay hydrated and take proper precautions."

Safety steps include drinking lots of water and staying out of the heat. Hoxsie said people using fans to stay cool should know the moving hot, dry air contributes to dehydration.

Staying indoors isn't an option for firefighters battling hundreds of small flare-ups and some larger Southern California blazes. Three firefighters battling the Border Fire southeast of San Diego were treated for heat-related illness over the weekend, Cal Fire spokesman Daniel Berlant said Monday.

"Cramping of the muscles, blurry vision, lack of energy are all the first signs that an individual is beginning to take on some kind of heat-related illness," he said. "That starts with heat exhaustion, but it can lead to heat stroke."

The Border Fire started Sunday morning, according to Cal Fire data, and had grown to almost 3 square miles and was 5 percent contained Monday. The towns of Potrero, Forest Gate, Star Ranch, Cowboy Ranch, Dog Patch and Canyon City were under mandatory evacuation orders.

The Sherpa Fire, burning more than 12 square miles northwest of Santa Barbara, was 54 percent contained Monday morning.

Berlant said extreme heat was only one factor that is increasing wildfire risk.

"It's really the low humidity, and also gusty winds that we're experiencing now in Southern California," he said. "These conditions allow fires to ignite more frequently and to become much larger much quicker."

Increased humidity, expected to arrive late Tuesday, could help slow some wildfire spread, but the sudden dampness can also cause more health problems, according to meteorologist Hoxsie.

"We will see a noticeable difference in mugginess and ability to get cool," she said. "When it’s a dry heat, you go into the shade, and you can feel a marked difference in the temperature. But when you get that humidity, you have to get somewhere where there’s cooling."

Though last year's destructive wildfires raised the question of whether California now has a year-round fire season, Cal Fire is still gearing up for what could be a roar of big blazes this summer. Berlant said Cal Fire crews responded to over 300 wildfires last week, and extreme hot, dry conditions that could continue through the summer are just beginning.

And there are more standing dead trees. Berlant said the estimate stood at 29 million at the end of last fall, "but that's likely to double if not triple this year."

"This year we were lucky enough to receive some rainfall across many parts of California during the winter and the spring," he said. "But conditions are already drying out very quickly. ... Those millions of dead trees are just a huge concern for us."