So I need to find this out but can't seem to find a simple answer anywhere on the internet. I am planning on purchasing a geiger counter as preparation just in case WW3 actually happens. The display of the one I'm counting on purchasing reads in msv. I'm trying to find out what reading, very roughly, is high enough to warrant needing to leave a particular area? Basically, what is the minimum reading on a geiger counter in msv where one should leave, or start to use a respirator? A simple rough numerical value would be welcome. Every article I've tried has just been bullshit about how "muh you can't trust geiger counters, radiation is complicated", fucking patronising nerds can't give a simple answer.