Will It Hurt My Flat Panel Tv To Mount It Over The Fireplace?

About the only place on the wall I want to put the tv is above the fireplace but I have consern about the heat rising????

Does Hooking Up A Video Game System To A Flat Screen Tv Hurt It In Any Way ?

My wife and I are considering buying a new Vizio LCD t.v. and I had heard (somewhere ?) that they weren’t good with video game systems. Not sure why, that would be, but I’d hate to spend the money on a new T.V. and have it messed up by a game system.