Staying cool was the order of the day but not everyone could.

Not only that but most cooling centers aren't open this weekend.

This record-setting heat wave in North Texas made Pedro Ruiz's job a lot tougher.

This construction crew has been working more than nine hours in triple digit weather, pouring asphalt and concrete on Butler Street and Harry Hines Boulevard.

"Actually, this material is up to a 130, a 140... it is even hotter when they bring it," said construction worker, Pedro Ruiz.

Ruiz is on high alert.

He is filling up the water coolers, trying to keep his crew hydrated and safe.

"We try to stay cool out here in these hot temperatures because you don't know what could happen," he said.

In Dallas County, the summer has already turned deadly. Three people have died because of the heat.

Doctors say hydration is key.

"If you notice that you are outside in the heat, sweating for awhile and you stop sweating, it's very important that you go inside. Really staying hydrated is the most important thing to do, and avoid the heat if you can," said Dr. Andrew Rubin from Harris Methodist Hospital.

The Dallas County medical examiner confirmed three heat-related deaths on Saturday.

E-mail mdiaz@wfaa.com.