Flex Alert in effect Tuesday, Wednesday afternoon amid heat wave

With a heat wave gripping the region, the manager of the state's power grid issued a Flex Alert that will be in effect Tuesday afternoon and Wednesday afternoon, urging residents to voluntarily conserve electricity to ease demand on the system.

The Flex Alert issued by the California Independent System Operator, or Cal-ISO, will be in effect from 2 to 9 p.m. Tuesday and Wednesday.

Cal-ISO official urged residents to make an extra effort to conserve during late afternoon hours, when air conditioners tend to be used most. The agency predicted peak usage on Tuesday and Wednesday to exceed 47,000 megawatts, and noted that widespread air-condition use can put strain on the electrical system.

According to Cal-ISO's website, electrical demand late Monday afternoon reached nearly 43,800 megawatts. Demand on Sunday peaked at just more than 39,000 megawatts. The highest demand ever recorded by the system was 50,270 megawatts, which occurred on July 24, 2006.

A Flex Alert is issued when the electrical grid is "under stress,'' generally from increased power usage due to hot weather.

Cal-ISO officials urged residents to take steps such as:

Folks in Wrightwood were feeling the 90-degree heat on Monday after Southern California Edison shut off the power for the entire day to perform maintenance work.

Even though the power outage was scheduled in advance, a lot of businesses in downtown were affected, including the Wrightwood Market.

They were limited to one gas pump and had to use generators to stay open. "We can't do any hot food today, no microwave no hotdogs, anything hot that generates a lot of heat, we can't even do coffee right now." Said Kimberly Boyle. But sometimes the scheduled maintenance work is canceled due to the heat.

Southern California Edison says they look at several factors including:

Wrightwood was just one of dozens of areas with blackouts. Mike Shannon of Whittier says he understands the need to upgrade the equipment. "It doesn't bother me they've got to do it so if it's in the winter time it's cold and summer it's hot so they can't just schedule everything in the spring and fall.

Copyright 2017 FOX 11 Los Angeles : Download our mobile app for breaking news alerts or to watch FOX 11 News | Follow us on Facebook , Twitter , Instagram , and YouTube . Be a citizen journalist for FOX 11 and get paid - download the Fresco News App today.