That's not a valid fear, I guess. Even normally you might miss those so called emergency calls - (1) You are in a meeting and your phone is on silent (2) You ha

That's not a valid fear, I guess. Even normally you might miss those so called emergency calls - (1) You are in a meeting and your phone is on silent (2) You had few long chats over phone with friends/clients and your battery is dead (3) You are in a very crowded place or traveling and just couldn't hear your phone ringing (very common) (4) You obviously don't carry your phone in the bathroom; do you? At least, I don't. (5) And other technical/non-technical scenarios I can't think of right now. Also about these emergency situations, can you think of the number of times, you actually received these kind of calls? In last 8 years, I can't think of any. And let's say, even if there were couple of them, I think it is unreasonable to consider that 0.001% probability. In that case, you already have enough from the above 5 points to worry about.