HOUSTON -- It cooled down a few degrees for a couple of days, but the dangerous heat has returned and yet another heat advisory has been issued, KPRC Local 2 reported.

The National Weather Service issued the heat advisory for southeast Texas through 7 p.m. Friday.

"They're basically issued in 24-hour increments, and with the pattern not changing a whole lot, we may see this all the way through the weekend," KPRC Local 2 meteorologist Anthony Yanez said.

Thursday's high temperature is 100 degrees, but the heat index will make it feel like 105 to 109 degrees. The hottest part of the day will be from 1 to 6 p.m.

"Once you get above 105 degrees, certain people have a hard time with their body cooling themselves off," Yanez said.

The city of Houston also activated its heat emergency plan.

The city of Houston Health Department said a heat emergency is issued when the heat index reaches 108 for two or more days in a row.

As part of the heat emergency plan, the city designated libraries and multi-purpose centers as cooling centers.

Residents are urged to take precautions and stay out of the heat.

Yanez said it will be hot outside, but it will be even hotter inside vehicles.

"July has the highest incident rate of kids dying after being left in cars," Yanez said. "In 10 minutes, your car will go up 19 degrees. If its 100 degrees out there, it's 119 in the car."

After an hour, the temperature inside a car rises 43 degrees.

For safety recommendations about children and cars, read Anthony's Weather Blog.

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