..for like a day or two. some people do that to OVERHEAT their systems so they can return it in case something else breaks that isn't covered by the warranty, I believe.
I'm 99% sure that it overheats it. for the RRoD, bad soldering usually causes it and using the towel trick to heat up the system temporarily reconnects the solder point or something.
RRoD is covered by the 3 year warranty though, isn't it? why did you do the towel trick instead?