An intense heat wave is expected to linger throughout parts of San Diego County and Southern California for the next few days into the weekend, forecasters said Wednesday.

The unseasonable hot spell poses potential health hazards and sets a series of records for March temperatures, according to the National Weather Service.

An NWS extreme-heat warning will be in effect from 10 a.m. Wednesday through 8 p.m. Saturday for local desert communities, with temperatures of 104 to 112 degrees likely — and possibly a couple degrees higher on Thursday and Friday, with nighttime only lows falling into the mid-70s.

Into the weekend, temperatures across the county will be 20 to 30 degrees above normal for this time of year, according to meteorologists.

A less severe heat advisory will be in effect from 10 a.m. Wednesday through 8 p.m. Friday for the area mountains, with highs in the 90s possible below 4,500 feet and into the 80s at higher elevations. A heat advisory will remain in effect until 8 p.m. Friday for coastal areas, where highs could reach into the 90s, and the inland valleys, where temperatures in the triple digits are possible.

A slight cooling should move in over the weekend into early next week, with higher coastal humidity spreading inland. Even with the cooling, high temperatures for next Tuesday will range from around 5 to 10 degrees above average near the coast to 12 to 18 degrees above average for inland areas.

“Widespread moderate or greater Heat Risk will continue into the weekend except near the immediate coast and in the higher elevations in the mountains,” the NWS said.

Temperature records broken or tied on Tuesday (March 17)

Temperatures on Tuesday (St. Patrick’s Day) at San Diego International Airport raised the mercury to 89 degrees, cementing it as the warmest day of the year thus far, according to Meteorologist Greg Bledsoe.

Compared to other March 17 temperatures the NWS keeps on record, several areas around San Diego County broke their records for heat on Tuesday (with one tie). See those below:

• Chula Vista (93) broke its record from 1978
• Ramona (95) broke its record from 2004
• Alpine (96) broke its record from 1978
• El Cajon (97) broke its record from 1978
• Palomar Mountain (79) broke its record from 1972
• Campo (89) tied its record from 2007

Also on Tuesday, Ocotillo Wells was the hottest spot in the entire county at 102 degrees! While the desert is expected to be sweltering, San Pasqual was the hottest spot not in the desert at 99 degrees.

How to keep cool amid heat waves:

Cal/OSHA, for its part, urged employers to take precautions to protect workers as temperatures rise.

“This is one of the first heat waves of the year, with temperatures rising above the seasonal average,” officials with the state agency asserted in a prepared statement. “Employees may not yet be acclimatized to high heat and may need additional breaks and interventions when they adapt to the conditions. Cal/OSHA reminds employers to be vigilant, especially with newer employees, and ensure that employees have shade, water and rest breaks to prevent heat illness.”

County officials offered tips on how people and their families can stay safe:

• Drinking plenty of fluids
• Stay out of the sun
• Wear light, loose-fitting clothing
• Avoid using the oven to cook
• Limit strenuous activities to early morning or evening
• Take refuge in air- conditioned spaces if possible
• Check in on potentially at-risk friends, relatives and neighbors

How to help someone with heatstroke or heat exhaustion:

First and foremost, if you find someone who is suffering from symptoms of heatstroke or heat exhaustion — dizziness, nausea, confusion, headache — call 9-1-1 and start cooling them. DO NOT give them fluids to drink. A person with heatstroke may not be able to swallow. Fluids could run down their trachea into their lungs and make it hard for them to breathe.

After calling 9-1-1, start cooling the person by moving them into the shade, spraying them with cool water and fanning. Place them in a cool shower if they are alert, monitor their body temperatures and continue cooling them.