Last month, I used camper (and enclosed internal space) to program a brand new ham's HT to certain frequencies related for an off-road "endurance" 100k event; held in challenging high altitude terrain (high Sierras). This was the new Ham Operator's first ever support event; we both were called in from "out of the area" to help provide support. The camper provided me with a sheltered space within which to perform this programmiung.
Much later that day, we had a runner go missing and close to midnight we started a search effort using the local County's Search and Rescue team. We're in an area well out of cell phone range. She was lost somewhere in a 4.7 mile trail stretch, extreme darkness and temperature dropping. The new Ham was dispatched (with his HT) with the S&R team to the field. I maintained a radio link in my camper using antenna mast with him and local Net Control. Around 12:20 am he was ecstatic to report over radio that they had found her! She was quite disorientated; she reported "blacking out" and didn't recall ever passing through the previous aid station.
She was transported to town and recovered quickly.
The use of the truck camper provided a great temporary, remote and weather protected "base" station; we were well off-road and out of cell range; very remote (4WD, "off grid"). I had previously provided external Anderson Power Poles and "through hull" antenna connections to keep us working during this event.