Most of those services use a different network, or their devices are flagged as emergency numbers and get some priority. Why doesn't the call from a paramedic or other emergency number go through as a high-priority call and indicate as such? When I call 911 my cell goes all nuts telling me about how it's got priority service and the UI changes to an emergency-colored UI with some additional information, so when they call me when my wife is in the ER, why not have the phone go nuts and force me to answer it?