They had issued a flex alert through the weekend, but now it's only in effect today, which should be the peak of the heat wave. The basic message is to make an extra effort to conserve energy between 11 a.m. and 6 p.m. I don't know where you are, but here in Westwood the heat doesn't seem to be quite as bad as had been predicted. From a DWP release:
Energy demand in Los Angeles reached 5642 megawatts Thursday but today's demand is expected to approach higher levels, as the heat wave reaches its peak intensity, with temperatures exceeding 100 degrees for the fourth straight day in the San Fernando Valley. LADWP's all-time high energy demand was 6177 megawatts, recorded on September 27, 2010. Despite the high temperatures, the LADWP system has functioned well and power outages have been minimal. However hot weather can lead to outages- and for a variety of reasons. The heat not only leads to more people operating their air conditioners all at once but also causes other appliances to work harder in order to perform. This puts strain and stress on electrical infrastructure and can overburden power lines, transformers and other equipment, causing them to fail. It can also trigger substation circuit breakers or other electrical equipment that is designed to protect the system to shut down automatically before serious damage occurs.