About 120 San Diego Unified School District schools without full air conditioning had "minimum day schedules'' Monday, including Clairemont, Crawford, La Jolla, Madison, Mira Mesa, Mission Bay and University City high schools, according to the district. District officials said Tuesday's schedule would also be shortened.
"It's like a snow day for us," said parent Paul Moss who's child attends McKinley Elementary in North Park.
Many classrooms at McKinley Elementary aren't equipped with air conditioners, and students complained of headaches, sweating, and loss of concentration.
"Can't concentrate on anything, it's crazy," said Elliott Blankenship.
After-school athletic activities have been canceled at all city schools.
While campuses in the valley areas generally have air conditioning, many of those closer to the coast aren't as well-equipped. A full list of schools is available on the district's website, sandi.net.
Sweetwater Union High School District officials have implemented a minimum schedule at Mar Vista Academy, Castle Park and Hilltop middle schools, and Chula Vista, Mar Vista and Sweetwater high schools.
The Coronado and National school districts also implemented minimum days Monday and Tuesday.
Utility officials were urging everyone to scrimp on electricity until after the heat of the day.
A National Weather Service heat advisory for the valleys will be in effect until 7 p.m. Tuesday, as high pressure and a weak onshore air flow help push highs to near record highs.
Forecasters said highs would be in the 80s along the coast, in the 90s a few miles inland and more than 100 degrees in the inland valleys.
"Abnormally hot temperatures can be stressful to animals and humans, making it hard for the body to acclimate and remain hydrated,'' according to the weather service advisory. "Without precautions even healthy adults could experience heat stress and illness.''
More than 100 air conditioned buildings like libraries and recreation centers will be open to those trying to beat the heat. County "Cool Zones'' are marked with a light-blue polar bear logo.
A list of county Cool Zones is available at CoolZones.org. or by calling 211, according to county officials.
A "Cool Room'' has been set up at San Diego Christian College in Santee to help those without air conditioning stay cool, city officials said. The room will be staffed from 1 p.m. to 6 p.m.
The heat wave also prompted San Diego Gas & Electric to ask its customers to lighten the load on the electrical grid by reducing consumption between 11 a.m. and 6 p.m. SDG&E customers who participate in the "Reduce Your Use'' program could receive credit for doing so, according to the utility.
Forecasters advised area residents planning outdoor activities to schedule them for the cool of the morning or in evening, to take frequent breaks in shady or air conditioned areas and to know the signs of heat exhaustion and heat stroke. Those headed outside were advised to wear light, loose clothing and to drink plenty of water.
Weather service forecasters said temperatures would cool Tuesday and Wednesday, but an "influx of monsoonal moisture from the south,'' thanks to Hurricane Odile over Baja California, would cause humidity to rise.