Fire officials pleaded for additional manpower to battle a 7,000-acre wildfire near the California-Mexico border as stifling heat continued to bake the state in triple-digit temperatures.

The blaze had burned nearly 11 square miles of brush and chaparral in the Cleveland National Forest in southern San Diego County. About 500 firefighters on the scene had contained only about 5 percent of the fire late Monday in its third day of burning in the largely unpopulated area.

Several lightning-sparked wildfires have scorched the state in recent weeks, straining firefighting resources. Firefighters trying to contain the forest wildfire were awaiting relief from firefighters and equipment tied up elsewhere.

"We're really strapped right now," said U.S. Forest Service spokesman Jake Rodriguez. "We're putting in orders for more men and more air support, and we're just waiting for them to be released."

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The blaze prompted sheriff's deputies to order 125 homes evacuated in the town of Alpine starting Sunday. Residents throughout parts of Pine Valley and Lake Morena, where there are about 1,350 homes combined, were told to remain on standby, said sheriff's spokeswoman Susan Plese.

More than 1,500 homes and 100 commercial properties could be threatened by the fire, but the threat was not immediate, officials said.

Fire crews have had to work through 10 straight days of a heat wave that has sent temperatures soaring above 100 degrees through much of the state. At least five firefighters around the state have suffered heat-related illnesses in recent days, officials said.

"If you get behind on drinking water, you can't catch up," said firefighter Jon Sanchioli, 46, who was protecting structures from the forest fire. "We had one guy go down yesterday. We know you've got to be careful. If you keep on pushing, your body shuts down."

In Joshua Tree National Park — where another blaze had consumed about 1.5 square miles of dense, desert vegetation — temperatures reached 103 degrees Monday. Fire supervisors asked crews to remove their helmets every hour to make sure they were still sweating, fire spokesman Dennis Cross said.

No sweat, he said, could mean a firefighter had "dried up" — a sign of heat exhaustion.

"It probably feels like it's 150 up there," Cross said, adding that crews were drinking about the twice the amount of water and Gatorade they might otherwise consume.

Farther north, more than 800 firefighters worked to cut lines around an 8,200-acre — or nearly 13-square-mile— blaze on ranch land east of San Ardo in southeastern Monterey County. A lightning strike late Saturday sparked the fire and erratic winds generated by thunderstorms caused it to spread, officials said.

Off the coast, a lightning-sparked fire on Santa Catalina Island was 80 percent contained Tuesday at 1,094 acres, or 1.7 square miles, with full containment expected by the end of the day, fire Inspector Edward Osorio said.

"Pretty much the fire has died down ... just a few hot spots," he said.

Fire crews in neighboring Arizona virtually contained a wildfire that had threatened to reach two power lines that feed electricity to the Phoenix area. By Monday afternoon, officials declared the fire 95 percent contained, with full containment expected Tuesday morning.

Milder temperatures and increasing humidity were helping fire crews beat back three blazes burning in timber stands along the rugged slopes of the central Idaho mountains.