Either the temperature reading is FALSE because of a failing instrument or sensor - in which case you need to get it fixed because you won't be able to tell when the engine is really overheating... OR....
The temperature gauge is telling the TRUTH in which case you'll need to get it fixed before the engine seizes up at great expense.
It may be that the engine's cooling system is not working as it should - high temperature AND the engine warning light are sending out a strong message to you.
Good luck...
Peccavi
September 2009