Well, as long as you don't traipse too hard --or maybe slow it down to an amble-- keep moving until something stops you!
It is safer to take someone with you, but if you can't or won't drag someone along, bringing a gadget along so you can let loved-ones know you're okay, or not, is fairly easy. The hard part is deciding what to bring.

Your question is very pertinent, as there are several options nowadays and there's a lot of recent innovation in this area, built around hiking and backpacking.
1. Personal Locator Beacons have been around for years and are very durable SOS-only gadgets. Press a button and emergency personnel come get you.
2. A few years ago, several companies started making what they call Satellite Messengers. With those, you can do an SOS, plus have the gadget send your location and text messages. All this is done via satellite so you don't have to rely on cell service. This is the most popular option currently, since it can be a backup to your phone for communicating with loved-ones and emergency personnel. Also useful for road trips and other situations where you may be out of cell range.
3. Apple's latest iPhone has some of the Satellite Messenger functions, so if you're already comfortable with iPhones, that can be a option if you don't want to deal with two gadgets.
4. A radio or walkie-talkie can work too, but only if someone else is also using one too and is listening. Everyone uses cell phones, so this tech has largely fallen out of favor.

I need to decide on this kind of thing myself, even though I usually go with the same guy for every trip. Eventually, he's going to get tired of me.