D7000 video question
From what I understand, the video time limit on the digicams is imposed due to law, not an overheat issue. It's so the camera market won't infringe upon the camcorder market. If it hasn't happened already, I believe this issue is in the courts to have that time limit removed. So don't worry about heat unless your camera gives you a heat warning I also believe there are pirated firmware's which have removed that time limit which a good old Google search could find you. But beware if your camera is under warranty it would void it!