Personal Location Beacons (PLBs) and satellite messengers have really been expanding lately. Lots of options out there. I'll mention a few but I am not suggesting these are the best.

The cheapest option is a PLB with no 2-way communication option. If you are in an emergency you activate the device and it sends your distress call along with position to emergency management system. You cannot send anything else with these devices and the emergency response cannot send you any information. ACR ResQLink is a popular option.

Garmin inReach is a popular messenger. It has the functionality of a PLB but adds the option of messaging. You can communicate with friends and family in non-emergency situations, too, including sending your coordinates. Such that if you became incapacitated they could communicate your last known location to potential rescuers. That additional capacity comes with, not just upfront costs, but access costs, too. The plans have been coming down in price but are not cheap for the occasional trip (most require an annual fee): https://www.garmin.com/en-US/p/837461

Satellite phones are the next step up both in terms of communication ability and cost. The latest in this front is the iPhone14 has built in capability to place satellite calls. I consider it more of a luxury item than a safety item particularly in terms of battery life. The inReach will last two weeks on a single charge. If you are bringing your iPhone you better have an awful lot of battery chargers (lighter than solar panel in most situations).