You are alone and find an infant who is unresponsive, is not breathing, and does not have a pulse

Hopefully, you have a cell phone so you can call 911 as you start CPR. If not, hopefully, the child is small enough you can carry them quickly to somewhere you can use a phone. Getting professional help on the way is the most important thing you can do.

Hope that helps.

The higher you go up the less oxygen there is