I was looking at this just yesterday, Riecoin only has a CPU mining client and is tradable on Poloniex. ypool is the only pool I know of, however. You might be able to mine Primecoin, as well, although there are GPU miners for that.
It would help if you were to post an error log. You can bring this up by opening the console (One of the drop downs from the top) and press 'Start Mining'. Copy and paste the log from the console and we'll help you out on the errors. Just so you know, GPU Mining is on its way out, but you can still make a small amount of bitcoins from mining in a pool.
Unless you can bring the temperature down below 0 without water vapor forming, it isn't a good idea. Submerging your device in mineral oil would work, however.