It would depend on the gym, some gyms with the resources may take it's members out on some hikes, or other things like that, outside of the building. But others, like the one I go to, this means that you are going to be assigned a partner and will be doing extreme workouts.
Probably work out a lot, keep exercising, presumably over a day or two. Hard-out work-outs though, plenty of push-ups rather than star-jumps. As it's called a boot camp, I'd personally expect it to be very hard and very physical - not my kind of thing at all.
It's going to be very similar to the ones on TV. If you haven't seen " The Biggest Loser," " Celebrity Boot Camp " be prepared for a butt kicking. Running, weights, diet, resistance training. Good results.