A second Minus 5 Ice Lounge location will open at Monte Carlo in the space currently occupied by the Lance Burton Magic Shop and an MGM Mirage Players Club kiosk. The first Minus 5 in Vegas is at Mandalay Bay.
Minus 5 is a bar which is made up entirely of ice. Before entering you are given jackets, gloves and boots to wear. It's $25 to get in, and that includes 1 drink. I seem to remember there being a time limit that you could spend in the bar, but I'm not sure if that still exists. I can't imagine people hanging around very long either way.
When the first location opened I was wondering how successful they would be. The overhead must be insanely high, and the bar is pretty small, but apparently they are doing well enough to open a second location. I've never been there but it's probably worth doing once for the experience. They also have some pretty cool specialty drinks, including some named after Las Vegas Celebrities.