Tips to beat the heat
• Slow down. Be your most physically active during the coolest part of the day, usually between 4-7 a.m. Pace yourself when engaging in physical activity.
• Stay indoors as much as possible. If air conditioning is not being used, stay on the lowest floor. Keep shades down and blinds closed, but windows slightly open.
• Go to a Cool Zone site on hot days.
• Electric fans do not cool the air, but they do help sweat evaporate, which cools your body.
• Take a cool shower, bath or sponge bath.
• Avoid using the oven.
• Wear lightweight, loose-fitting, light-colored clothing. Light colors will reflect away some of the sun's heat.
• Air out hot cars before getting into them.
• Never leave children or pets inside vehicles at any time, even with the windows cracked. Temperatures inside a vehicle can reach lethal levels no matter what the weather is like.
• Drink more fluids than usual even if you do not feel thirsty.
• Water is the safest liquid to drink during heat emergencies. Avoid drinks with alcohol or caffeine; they make the heat's effects on your body worse.
• Eat small meals and eat more often. Avoid foods that are high in protein, which increases metabolic heat.
• Avoid using salt tablets unless directed to do so by a physician.
• If you take diuretics, ask your physician about a lower dosage during hot weather.
• If it is safe to do so, leave windows open at night. Open windows on two sides to create cross ventilation.
• Place a piece of cardboard covered with aluminum foil in sunny windows to reflect sunlight and heat away from the house.
• Vacuum, clean or replace air filters regularly for maximum cooling efficiency.
• If affordable, install outdoor awnings or sunscreens.
• Call your physician if you feel you may be experiencing a heat-related illness.
Source: San Diego County
We know it's hot out there — and going to get hotter. But what's causing it?
Forecasts say it's high pressure and offshore winds that are pushing temperatures into the triple digits in inland San Diego County this weekend and into the start of next week.
The unusually high temperature led the National Weather Service to issue a heat advisory for the valleys from 10 a.m. Saturday to 7 p.m. Tuesday. (Originally, the advisory was going to end Monday night, but forecasters have extended it a day.)
Higher than average temperatures on Saturday are expected give way to even hotter weather Sunday and Monday across coastal and inland areas in Southern California, with the highest temperatures in inland valleys, according to the weather service.
National Weather Service meteorologist Mark Meode says this system is similar to one that brought rain to the eastern part of the county recently. He says a high pressure ridge will allow hot air to build over California, Nevada and Arizona.
"This time of year is the best opportunity for us to get tropical cyclones to move up, like this one is doing. When that happens we feel this noticeable increase in humidity which is fairly unusual. Most of the year here we're very comfortable humidity wise, like a Mediterranean climate," Meode said.
Forecasters said temperatures along the coast would be in the upper 80s Saturday and lower 90s Sunday and Monday. Temperatures in the inland areas are expected to soar into the low 100s.
Related: Interactive map of Cool Zones in the San Diego area
"Very high 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.
Forecasters advised area residents planning outdoor activities to try to schedule them for early morning or evening, take frequent breaks in shady or air conditioned areas and to know the signs and symptoms of heat exhaustion and heat stroke. Those headed outdoors were also advised to wear light, loose clothing and drink plenty of water.
The hot and humid conditions are expected to push power usage into record territory. San Diego Gas and Electric officials are predicting a peak power usage of 4,800 megawatts on Monday. That would be the highest the peak the region has ever had. Even so, California power grid managers say there should still be enough power to meet demand. SDG&E spokesman Steven Greenlee says the summer has been relatively mild.
"We have not seen those kinds of unrelenting temperatures that would cause the kind of grid stress that we've seen in the past. So yes, I think we feel pretty fortunate. The other thing is too, is that we have not been plagued by fires. Taking out high voltage grid lines like we have had in the past."
It won't be as hot on Wednesday and through the rest of the week, the weather service said, but monsoonal moisture and clouds will replace the heat. In other words, we trade the heat for humidity.
KPBS reporter Erik Anderson contributed to this report.