How far to evacuate?

[Scythe13]

This is something I've been considering for a while now, how far away from a threat zone would be safe to evacuate to?

From a fire, it's pretty simple and common sense. But there are other situations that may not be so obvious. For example if you see groups people with eyes pouring, noses running and possibly even mouth foaming, it's time to run, as that's likely to be a chemical issue. You need to get away. But how far is safe? From Neil Strauss' book Emergency, he recommends 'The Rule of Thumb'.

'The Rule of Thumb': If you can put your arm out with your thumb up, and squint, if your thumb is covering the area of effect, you're out of the threat zone. That could be quite some distance, depending how close you are to the area of effect.

So, that's a good bit of information.

But the next question is, what's a good distance from a city or even a rural town?

Let's say TSHTF and there's riots in the street and it's not a good place to be. How far away would you be happy to evacuate to? Would your home be safe? Would your distance from town or shops make you a target?

So, when bugging out, how far do you think would be a good idea to get?