GMC 2009 Sierra - Manual (Page 91)

Windows
{ CAUTION:
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.
Manual Windows
Turn the hand crank on each door to manually raise or
lower the manual windows.
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