Here's a picture of me taken in Hardin's Cave by Tony Groves on our trip there back on February 8th. The person to the right is Steve Cooper, who is the president of the Nashville Grotto.
The pile of rocks, or breakdown, is typical of what you spend a lot of time crawling over in this cave. If you look closely you'll see I'm pretty sweaty at this point. Outside the cave it was abotu 25 degrees and snowing, but inside it was in the mid 50's and I hadn't figured out to unzip the overalls partway yet.
Steve is holding a slave flash unit, which is why it's so much brighter in front of him. The main flash from the camera causes the slave unit to flash a split second later. Often cave photographers will have multiple people holding slave units and can light up large areas of the cave that way.
Click on the picture for a larger version.