ICE stands for In Case of Emergency. It is frequently used to let emergency personel know how to reach someone (that you know) if you have an emergency.
How to use ICE:
Find someone that agrees to be your ICE partner. They should be easily reached and know your medical history.
Give your ICE partner a list of people to contact in case you have an emergency.
Now add your ICE partner's phone number into your cell phone but do not put in their name for that number, put in the capital letters ICE (unless your phone has an "In Case of Emergency" contact section).
Note: If you are a juvenile, make sure your ICE partner is a parent or guardian authorized to make decisions on your behalf.