If it's an electric gauge, can't be hurt by heat. Mis-wire, yes. Mechanical gauge: don't think so either. Why are you blaming the gauge? May be the sender. Aye? At any rate, check them on the stove!
My guess is that it is not over heating and I think that is what you are thinking also. Make sure timing is correct while you are at it. That can cause a little heat. If you have the correct radiator cap and thermostat and it is not boiling over like crazy, it's not hot.
