It's the sound of summer--AC units humming away under the blazing Texas sun.

25 consecutive days and counting of 100 degree temperatures--but there is another countdown--the one when the electricity bill arrives.

You know, the bill that people like Cynthia O' Kelly dread.

"Oh," Cynthia said. "It can be very scary."

On Facebook--Diana Groves Falt commented on the status of her electricity bills. "Last month was $640.00," Diana said. I'm dreading this months."

And this month many people may not be able to pay.

The Dallas County Health Department is flooded with calls from people who need help paying their bills. Low income residents can receive help if they meet certain qualifications.

Director Zachary Thompson said the only thing higher than the mercury is the number of number of phone calls.

"We are extremely busy in two areas, one people needing assistance with their electric bill and of course a lot of people who don't have working ac units.

Dozens of AC units were taken from the Dallas County Health Department and delivered to contractors who will install them in low income homes.

Thompson advises people to not worry about the bill, worry about your health.

"The tragedy is really worrying about the bill and putting your health at risk," Thompson said. "I think we should just focus on running the AC unit and then contact us to see if we can assist you with your electric bill."

TXU energy experts suggest that you can save money by turning off your lights, don't charge your smartphone all night long and monitor the thermostat.

"One of the things we recommend is setting your thermostat at 78 degrees," Kim Campbell, Senior Manager of Customer Advocacy said. "For every degree you lower that you are spending 8% more per degree on your electric bill."

When you're talking 100's of dollars that can be a nice chunk of change.

Remember homeowner Cynthia O'Kelly? She's not scared anymore because she signed up for the average billing program so that high bills are spread evenly over the year.

This month and every month her bill is $166.00.

In July, that's pretty cool.

"I'm not afraid only because I average," Cynthia said. "I'm not afraid."