IRVING (CBSDFW.COM/AP) – The evacuation order for part of a North Texas hotel has been lifted, after some people got sick from carbon monoxide exposure.

The incident happened Monday at Hyatt Place, on Green Park Drive, in Las Colinas.

Irving Fire Department Assistant Chief Rusty Wilson said a family of five at the hotel went to a hospital on their own after the adults and their children began experiencing headaches and nausea.

Wilson confirmed late Monday morning that the carbon monoxide leak was in the hotel boiler room.

Fire crews ventilated the building and just before Noon said CO levels were back to normal.  Hotel workers and guests were being allowed back inside.

As of the Noon hour, repairs continued to be made on the boiler and a fire unit will remained on the scene for continued monitoring.

Hyatt Place is a more than 120-room hotel.

(©2012 CBS Local Media, a division of CBS Radio Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)