In reply to Pietrach:
> Do you use such devices and what are the recommended ones? All it needs to do is to transmit a distress signal with location. No fancy functions needed.
Fortunately no experience of using one in anger, but have carried them in the past.
To be honest, for use on land there isn't much to choose between the 406MHz Cospas-Sarsat types (probably best if you don't want anything fancy like real-time tracking or two way communication etc).
I would advise you to read up on terms and make sure you are buying the correct type. 'PLBs', 'ELTs' and 'EPIRBs' are designations based on the specific code of the distress signal, and are for terrestrial, marine and aviation use respectively. However, in practice, pretty much everything is called 'PLB' when it is designed for personal use. Make sure you are buying the correct unit.
Also make sure it is registered and the information is kept up to date; it will make rescue much quicker should you need it. Even so, don't expect it to be near-instantaneous (as it might be with a phone). Usually rescue authorities will be notified within an hour of activation, but could be up to two.