CA Flex Alert extended through Friday as extreme heat causes strain on state's power grid

The manager of California's power grid has issued another Flex Alert -- a call for residents and businesses to voluntary cut back on power usage -- for Friday evening amid the ongoing heat wave.

The alert is in effect from 6 to 9 p.m. Friday.

The extreme heat gripping the state is expected to last through Friday, a situation that typically puts a strain on the state's power grid as air conditioners work overtime, particularly during peak afternoon hours.

The California Independent System Operator is calling on Californians to save power during what is expected to be triple-digit temperatures in many parts of the state.

Tips for responding to a Flex Alert:

* Adjust thermostat to 78 degrees or higher, or leave it off if you are not at home.

* Use a fan instead of air conditioning if possible.

* Close drapes and turn off unnecessary lighting.

* Avoid use of appliances until later in the evening.

Find more tips here.

NOTE: The video in the above media player is from a previous report.