The most "overload" I've ever experienced, as I recall, was while serving on USS Kitty Hawk in the Gulf. We (the carrier) were the launch platform for all the air strikes against Iraq in 1992 after Hussein had repeatedly violated the no-fly zone.
For two solid weeks, the ship was a home for more than 20 international journalists on a daily basis. By home, I mean they lived on board. My boss and I (Public Affairs Officer and PA Assistant, resp.) were responsible for getting them around the ship, setting up their interviews, getting their film/tapes off the ship quickly, and keeping them berthed (i.e, with a place to sleep), in clean clothes (having their laundry done) and well fed (ensuring they made all the meals). They set up satellite dishes on either side of the ship to transmit video and audio and were quite an attraction for the crew.
I averaged 4 hours of sleep a night (if that) for the duration of their visit. While we averaged 20 people staying overnight, we had daytrippers, too, and sometimes had as many as 40 media on board at any given time during the day. They, then, had to be booked to fly off at various points.
In addition to that, I was still responsible to ensure our dailly newspaper got published and that our television schedule stayed on track.
I've never been more tired -- or satisfied with the end results -- in my life.
I've had other "overloads" that were more mental than anything else. And always because of dimwits I had to work with or around.