PALM SPRINGS, Calif. -

A strong ridge of high pressure will cause a heat wave in Riverside County from Friday to Tuesday, likely setting new record high temperatures throughout the region, meteorologists said today.

According to the National Weather Service, the hottest days will be this weekend.

An excessive heat warning for the mountains and Coachella Valley is scheduled from 10 a.m. Friday to 8 p.m. Sunday. An excessive heat warning will be in effect from 10 a.m. Saturday to 8 p.m. Sunday in the Riverside-Ontario-San Bernardino metropolitan area.

The weather service said highs over the weekend will range from 115 to 120 degrees in the Coachella Valley, 100 to 105 in the mountain foothills, 90 to 100 in mountain areas around 3,000 to 5,000 feet, and 100 plus around Riverside.

``Exceedingly high temperatures can cause heat-related illness or death,'' an NWS advisory said. ``Those working or playing outdoors, and those without air conditioning are most vulnerable.''

To avoid heat-related illness or death, residents are encouraged to wear light-weight, loose-fitting clothing and if possible, reschedule any planned strenuous outdoor activities to early morning or evening hours.