Emergency
With Automatic Crash Response, the built-in system can automatically connect to help in a crash even if you cannot ask for it.
Push 
to connect to an Emergency Advisor. GPS technology is used to identify the vehicle location and can provide critical information to emergency personnel. The Advisor is also trained to offer critical assistance in emergency situations.
See also:
Insuring the Vehicle
Protect your investment in the GM vehicle with comprehensive and collision insurance coverage. There are significant differences in the quality of coverage afforded by various insurance policy terms.
...
Store a Name Tag for Speed Dialing
1. Push System responds: “OnStar
ready.”
2. Say “Store.” System responds: “Please say the number you would like to store.”
3. Say the entire number without pausing. System responds: ...
Running the Vehicle While Parked
It is better not to park with the engine running. But if you ever have to, here are some things to know.
WARNING
Idling a vehicle in an enclosed area with poor ventilation is dangerous. Engine exhau ...