These days with texting and emailing it's even easier. You can just set it up with a friend or relative that you text or email each day (with no response required).
A woman once called me to buy a copy of an academic journal we published. Her son had an article in it. He had died - he was an assistant professor in his 30s, lived alone, had a heart attack, and was discovered dead a couple of days later. That's always stuck with me.