I hate to be a spoiler, but there is a potential pitfall with the ICE concept:
An email "warning" was going around that turned out to be legitimate, or at least possible. It went like this:
A man received a text message from his wife's cellphone saying that she was at the bank but forgot their ATM PIN number, and asked him what it was. He replied & sent it to her phone.
Twenty minutes later he received a phone call from his wife, from a land line. She told him that her purse had been snatched a while ago, along with her wallet, credit cards, and cellphone. And NO, she did NOT send him a text message asking for their PIN.
The thief went through the cellphone's address book and sent the text message to "Hubby" asking for their PIN. Within a few minutes, with the wife's ATM card, he cleaned out their bank acct.
Although unable to verify if this actually happened, SNOPES considers it a
"cautionary tale" that quite possibly could happen.
Now, it would be just as problematic to have "ICE" numbers that a thief could text message the same thing, in the hope that one of them would provide the PIN. In any case, they recommend that you advise no one ever to text a PIN number even if you ask for it... To call you back.