Con Edison set an all-time record for peak electricity demand Tuesday as Bronx residents turned to air conditioners, cooling centers and even fire hydrants to escape the heat.

Despite guidelines issued by Con Ed ? including setting air conditioners to 78 to prevent city-wide power outages -- the utility reported an all-time record for peak electricity demand, breaking the record set last year by 44 megawatts.

As temperatures continued to hover in the high 90s, the New York City Department of Education made summer school attendance optional. The fire department began dispensing fire hydrant sprinkler caps to residents wishing to cool off under the spray of water. At risk residents, including those with heart and respiratory conditions and the elderly, are being urged to stay indoors until the heat wave passes.