Always call 911 first before administering CPR or using an AED. The timing of the use of an AED first depends on how accessible an AED is. If an AED is immediately accessible, get the AED and use it right away. However, in all likelihood, there will not be an AED close enough and CPR should be started first.

If the person doesn't respond and you're with someone else who can help, have one person call 911 or the local emergency number and get an AED if one is available. Have the other person begin CPR. If you are alone and have immediate access to a phone, call 911 or your local emergency number before starting CPR. Get an AED if one is available.