What is the best way to track someone with dementia?

Donnie lost a friend affected by dementia, and would like to know what sort of device could have been used to locate him

A former colleague developed dementia. He wandered off and was found three days later in a small wood a few miles away. Sadly, he died on his way to hospital. What sort of electronic device could have been used to locate him sooner?

I'm 85 and a Guardianista since 11 December 1953 (National Service call-up). Donnie

Location tracking is a rapidly growing field, to the point where it looks as though almost everyone will be tracked within the next decade or so. Parents are tracking children and pets, and sometimes their own parents. Health services and care homes are tracking patients. Local authorities and other employers are tracking lone workers, for safety reasons. Distributors and delivery services are tracking vehicles and sometimes couriers. Military organisations are tracking soldiers. Millions of people are using fitness bands to track themselves, their heart rates, their sleep patterns and so on.