2003 GMC Yukon Owner's Manual - Page 108

Windows {CAUTION: Leaving children in a vehicle with the windows closed is dangerous. A child can be overcome by the extreme heat and can suffer permanent injuries or even death from heat stroke. Never leave a child alone in a vehicle, especially with the windows closed in warm or hot weather. Manual Windows Turn the hand crank on each door to manually raise or lower the manual windows. 2-14