GoPro Fogging up issues - a cheeky fix?

Talking with a mate in work today, he's got a GoPro, but an older model, I suspect that the Hero 2 might run hotter than the Hero. He passed on a tip he'd heard to help stop the fogging issues. A small pieces of loo roll folded up tightly and placed in the sides and top of the case help absorb the trapped moisture and (I'll say reduce rather than stop) the fogging issues. I'll certainly give it a try next time I'm out with the camera, will have to keep an eye on the temperature of the camera.