1998 passat 1.8L turbo TEMPERATURE WARNING LIGHT

Hi, I just got the car and now as soon as I start it, or sometimes when driving, the temperature warning light comes on.... Beeps a lot then keeps on flasing. Could it be an error? I do not think the temperature sensor has gone wrong BECAUSE it the needle rises up accurately and stays in the middle. What could it be? Should I keep on driving?

I touched (feel) the radiator hoses, one APPEARS to be warm and one appears to be empty and cold. I am not sure of this, since I was hurrying, it is severe winter here in quebec. But then again, why would it keep on beeping the second I start it, in freezing temperature? It would take at list a few minutes to warm yup ...blah blah blah. If this is simply an error, how can it be fixed?

HELP !

What color does it flash blue or red? Does the mfi say "check coolant?"

There is a level sensor in the resivour that sometimes goes bad.
Also if the coolant hoses are cold and warm than you may have a stuck thermostat.