Psycho Temp Gauge

I just bought a 2001 Jetta 2.0 - My temp gauge is psycho - For seemingly no reason it will go all the way to infinity and stay there and then after two starts or so later reset and work fine - I don't think that it is overheating - Yesterday drove a lot in 100 degree heat with a/c in stop and go traffic - my gauge did this a couple of times - i checked under hood - no abnormal heat smell, no hiss, no leaks was running GREAT - does anyone know what to think or do about this? Should I be worried? Thanks!!!!runaround

Replace the coolant temp sensor