Uptime Status reflects if a system at a Location, or indeed if its associated tablet(s), is in an offline state and demands attention.
You can navigate to the Uptime Status by choosing it from the navigation toolbar at the top of the Remote Supports Dashboard, from any given page.
Once there, you will see a list of Locations (if any available) with a currently-offline device or hub.
This allows you to address, as a Remote Supports Professional (Provider), instances of outage as quickly as possible and to decide how to follow up on the situation.
Your Locations (ostensibly) will be outfitted with battery back-ups; these will be included in any given Location's Sensor List, available on the Location Details Page, and can be checked for an at-a-glance understanding of whether it's powered and powering the hub, or if it has been depleted. This can sometimes occur, due to any number of reasons, and after (some amount of time) the battery back-up will completely deplete. In this case, it merely need be plugged back into the wall outlet from which it was unplugged.
Check this out by looking at this in the Sensor List:
