The other day I was over at Allan's house and I noticed that he had a sauna. Being a skier, the first thought that crossed my mind was, "I bet I can make that thing work as a hot box!" So I immediately turned on the sauna, ran out to the car to get my skis, and then threw them in! It worked perfectly too! The sauna is meant to hold like 3 people (I think Allan set a record with 15 or 16 in there once though), and there's just enough room diagonally for the skis. Even better, there are these horizontal slats that work as ski holders.
So I dumped my skis in and was just hanging around the house when Allan showed up a while later with my skis in his hands. Apparently he didn't approve of me totally violating the proper usage of his appliances. However, when I went into the sauna room later, it was stacked full from top to bottom with Allan's skis, so there you go.
So, if you're thinking of spending some money on a hot box, I'd say you should get the two for one deal and buy a sauna instead. I was talking about this with somebody recently and I think there are some pretty inexpensive kits out there to be found. Here's one at Amazon for only about $800. If anybody finds anything cheaper anywhere else, just let me know (put it in the comments)!