Why heated seats on a 2008 saturn vue went cold.

They are timed like rear demist, the manufacturers reason this.... Starting a cold car takes time to warm up so they give us heated seating. As your journey continues the car gets warmer as the engine heat is directed towards the cabin via vent settings. The seats are power hungry and require much juice to heat so as the cabin temp rises, it takes over the job of heating your whole body and not just your posterior (so to speak), the seats will automatically switch off. Press the button again and they should come back on for the prescribed time.

Or could be a blown fuse !
Red.