PASADENA  (AP) — Six half-marathon runners were taken to the hospital Sunday for heat-related illnesses as Southern California again broiled in sweltering temperatures, authorities said.

The runners who required medical attention were extremely dehydrated and some experienced cramps, said Pasadena Fire Department spokeswoman Lisa Derderian.

The race, which began at 6:30 a.m., took its toll toward the end on some participants, who stopped short of the finish line, Derderian said.

Paramedics were scattered along the 13.1-mile route in Pasadena and evaluated dehydrated runners who did not need to be hospitalized. In a typical race, they would see more sprained ankles and falls than heat-related problems.

Marathon organizers urged runners on its website to stay hydrated and promised extra water and ice towels along the route. Buses with air conditioning were provided for runners to cool off.

The event was supposed to be a marathon, but was changed to a half-marathon long before the heat wave due to low turnout last year.

“If this was a full marathon, we would have definitely been responding to a lot more calls,” Derderian said.

Valley and desert regions prepared for another day of triple-digit temperatures Sunday, which weather forecasters said could be the hottest day.

Several Southern California communities set same-day record highs on Saturday including Palm Springs, where the mercury hit 122 degrees.