Dial 911 from virtually any cell phone and hang up. No need to say anything.

PS. 112 in Europe.

(edit) I meant to say that American 911 is European 112. I don't know if the police in European countries is supposed to react to dropped 112 calls or not. In Canada and in the US it is. A friend of mine saw it in action. He saw something, dialed, realized it wasn't a big deal, hung up, walked away 100 m, then, boom - not 2 minutes later a fire truck and a police car exactly where he called from. Their precision was really freaky.

FYI, 112 will actually work on /any/ GSM phone, no matter where you are (provided there's GSM reception in your area, naturally). It's part of the GSM standard; 112 is supposed to redirect to whatever your local emergency line is.

Even more so, 112 is the only number you can dial on a GSM while the keypad is locked.

I'm not sure how it works on all European countries but at least on my home country if you do call 112 and hang up nothing is going to happen. If you call 112 and say something and the call gets cut for some reason nothing is going to happen either...

in my home country you're lucky if they pick up the phone before you bleed out.

the thing is, 'europe' is a true overgeneralization, every country has different qualities of handling 112 emergency calls.

German anecdote: A few years ago my 2yr old son seems to have dialed 112 by accident. We learned about this a minute later when the fire department called back to check if we needed help.

When my kid was three or four, I called the sheriff's business number, asked to talk to the 911 office, and asked them if I could have my son dial 911 and talk to them, for training (his). They checked if they were busy, then said OK.

It puffed up his chest a bit, but we talked about emergencies, how to get help, why we don't call 911 unless it's an emergency, etc.

I suppose if everyone did it they wouldn't be agreeable, but no one does, so you should too. :)

> PS. 112 in Europe.

This explains. My old phone with a physical keyboard would allow me to dial 112 even when it was locked.

It's part of the GSM spec to always allow a 112 call - even with no SIM or no account for the phone.

It's a bit of a problem in some countries - you get a lot of 'butt dialed' 112 calls - and the protocol in many jurisdictions if you have an emergency call and no voice is to assume the worst and send fire+police+medics

911 Operator here, most cities won't follow up a 911 hangup call from a cellphone unless there is reason to think there is an emergency. In large cities, you get hundreds of accidental 911 calls a day and finding all of the phones (even if they are WPH2) would take more than the entire police department only looking for 911 hangup calls. In many cities, a 911 call from a land line will automatically dispatch PD to the address.

Following the advice above is very dangerous.

If you can dial 911, don't just hang up, the response to that will vary from one place to another, even from one dispatcher to another. You need to find some way to make clear you're in trouble.

Echo this, recently a friend had an epileptic seizure in Switzerland and they not only wouldn't come right away, they made me very carefully justify why I thought they should come. It's my new rule not to assume this...

Good for them. Epileptic seizures aren't usually life-threatening.

Sorry-we had no idea of that not being professionals and she was blue and seemed not to be breathing. It turned out to be OK after the fact but at the time....

No. They can be. The probability is low, but during the Epilepsy the patient can injure himself.

Quite true. There are all sorts of pointy and/or hard things around that you don't notice until someone is having a seizure.

Yeah, probably better to just stay on the line, even if you have to keep your phone in your pocket or bag or whatever.

Two apps Circle of 6 and On Watch just won a government challenge put forth by VP Biden. The apps will be available in January, On Watch is similar to this product http://www.whitehouse.gov/blog/2011/11/02/announcing-winners... (FD: I'm the developer of Circle of 6)

Check out Guardly. I think they are doing something interesting this space: https://www.guardly.com/

Life360 (www.life360.com) has such a feature. It is essentially a safety app so families or groups of friends can keep tabs on each other.

Full disclosure: I interned with them a few years ago when they were a startup out of Berkeley. Looks like they've grown a lot since then.

I believe http://wisedameapp.com/ is intended to do something like this.

http://safekidzone.com/ being tested in california iirc

Actually, I was thinking that the whole network of users could be alerted, so people nearby, not just a call-center or 911. As usual, the issue is who to trust and not to trust from the userbase, but it's a problem worth solving - the equivalent of someone screaming for help.

in the UK they recommend that if you need help, you actually shout fire. Sadly in big cities people will 'put their heads down' and walk past muggings. The idea is that if you shout fire, then all those individuals are also at risk, and therefore come to help.