No, you wouldn't push the button unless your symptoms get worse. If you're becoming incapacitated from either pain or weakness so that you can't get to more water, if you (as I mentioned in the other thread) start having appendicitis symptoms, then it does become a life-and-death emergency. A sneakier possibility is if you keep barfing up part of the water you are drinking and/or keep having severe diarrhea. I found out with one of my sons (who got food poisoning on a weekend outing) that this can lead to severe dehydration within a couple of days. He ended up in the hospital!

With the symptoms you describe, you could probably rest a day and then start walking out, although you might have to take it pretty slow. If the worst came to the worst, you might meet SAR on your way out.

US Federal law is pretty specific on the "life-or-death emergency" that must exist. I don't know if I would want to test this clause just to save SAR some extra work! The regs may be a little different in Canada.

I tell my family (daughter-in-law) to wait 24 hours after I expect to be out and within cell phone range (which may be several hours' drive from the trailhead). If I bust a leg the second day of a long trip--well, that's what my PLB is for!

I, too, would like to hear from SAR folks about this. Anybody out there connected with the Coast Guard (and therefore familiar with Federal regs on PLB use)?