2012 GMC Sierra Owner's Manual - Page 63

Keys, Doors, and Windows 2-19 Windows { WARNING Leaving children, helpless adults, or pets in a vehicle with the windows closed is dangerous. They can be overcome by the extreme heat and suffer permanent injuries or even death from heat stroke. Never leave a child, a helpless adult, or a pet alone in a vehicle, especially with the windows closed in warm or hot weather. pulsing sound when a window is partially open. To reduce the sound, open another window or the sunroof (if equipped). Manual Windows Turn the hand crank on each door to manually raise or lower the manual windows. The vehicle aerodynamics are designed to improve fuel economy performance. This may result in a