Is it safe to mount a plasma TV above a fireplace that has a wood burning insert with blowers on it.?

Put a thermometer in the location that you wish to mount the tv, start a fire and monitor the temperature. If it gets much hotter than the rest of the room, you will cook your tv to death. If, however the temperature does not get very hot then temperature wise it will be ok. As for mounting safety, that has to be discussed with someone who has experience in mounting above fireplaces.