That’s his first mistake, taking the phone into the woods.
edit: Hey gang it’s me, dipshit. I made this comment in jest originally, because the guy wasn’t really using it as a rescue device to begin with, and because there are some legitimately good reasons why you may want to leave your phone at home or in the car, depending on your goals. Assuming you want to survive, yes, you’ll probably want to bring your phone with you but depending on your equipment and certification you may have even better options.
If you’re going an area where you know you’ll have service, taking a phone is a great idea unless your goal is to connect with nature and you feel the phone is going to get in the way of doing so (e.g., disconnecting from work or spending all day in your tent on the phone). If you take your phone with you and you have spotty service, try getting to a clearing or some view of a developed area or city - your phone is up so high that it’s going to have a pretty good chance at reaching some signal especially on LTE. Basically you have more signal “strength” and a greater distance with each foot you ascend.
If you plan to do this sort of thing often, you should probably get a device made for this sort of thing - one that has the ability to send short messages to 911 which can be done via satellites and not land-locked cell towers; one which has GPS and relays your coordinates to 911 or your friends / family at the push of a button. This comment not sponsored by Apple but the latest iPhones have this capability too.
If you’re going to do this sort of thing as a group at a large gathering like a festival or other event where you suspect the cell towers may be overloaded (e.g., burning man) you can use 900mhz mesh devices which support encryption such as meshtastic.org devices. This is a more diy solution but it allows your friends to have the p2p messaging via your phone’s bluetooth connection and the device, acting as a bridge to others.
There’s also satellite phones if you think you’ll need more than just basic 911 sms services out whereever you’re going. Or, if you have a ham operator’s license you can use portable equipment to talk to the next city, county, state or country over depending on a lot of factors.