PJM Interconnection, the grid operator, says it's extremely important to cut back on energy use between 6-10 a.m. and 3-9 p.m.
Set thermostats lower than usual, if health permits. The company also asks customers to postpone using major electric appliances such as stoves, dishwashers and clothes dryers until mid-day or after 9 p.m.
Also, turn off electric lights and appliances that you do not need or are not using.
The cold weather has also sparked a propane shortage. Gov. Pat Quinn declared a propane supply emergency in Illinois.
The announcement means that regulations for propane truck drivers are relaxed so they can drive to other states and fill their tanks. Illinois also has lifted limits on how long truck drivers can work within 24 hours. This will let them travel farther to pick up propane.
Wisconsin and Ohio have taken similar steps to deal with the extreme winter weather.