An 'ICE' one - but not one that allows access to the dialer. Simply a button on the unlock pattern screen which when someone presses it, gives basic health information/stats [like blood type, and a paragraph of known health issue or something]. So that nothing unlocks, people don't need to unlock it, so doesn't require knowledge of the pattern. Doesn't allow access to the dialer. Simply a 'if I can't talk I can poke and show you' button.
(Finally posting this in the right place!)
(Finally posting this in the right place!)