I've worked in companies that had staff entering remote sites and many without the ability to keep in contact (NZ & overseas). The staff either had e.g. mobile phone tracing connection, Location monitors which attached to their person (includes fall monitoring)..noting that some initially had nil or limited tracking equipment and relied on a JSA noting possible risks. The companies with staff entering a no-contact region ensured they had robust processes of notification/monitoring prior, included in e.g. JSA's, Hazard and Risk Registers. The companies also had procedures to have the staff 'check in ' once outside the area and also a company 'check the staff site exit process' .... to check the staff notified the company of exit and also to check if there was no staff check in carried out. One company, due to remote sites, also provided a 'rescue pack' should staff find it necessary to 'camp down' (e.g. injury, poor weather, vehicle problems preventing leaving, ) while the area e.g. weather settled/while the company sent out a 'finder' for the staff member. It took open and frank discussion with staff & was not a fast process, seeking out the appropriate supplied/tools for the company/staff/region. It took time to set up, train/practice as/if able, and also cost a committed budget. From this work there was also a process to extract staff from overseas environments detrimental to their health and safety.